So I have done a few play test games and read over the codex more and have some more opinions based on what is on paper and what I've been able to play test. I'll keep it clean and just focus on each category.
HQ
Hive Tyrants - Being BS4 is awesome, give it double twin-linked devourers and you are going to land 1.08 more hits than last codex (which can potentially mean another dead model) hitting 10.08 shots. Since they have dropped a little and wings have dropped incredibly, your going to see a lot more Flyrants flying around. One thing however is to remember that they are still very viable on the ground. Taking the Tyrant Guard gives them free LoS and wounds. Whether you equip them with devourers or a cannon, the Hive Tyrant has really pulled through for its shooting. Definitely a viable choice in a shooty army as an HQ. I would recommend two Twin-Linked Devourers if chosen as an HQ.
Tyranid Prime - A cheaper Tyrant, that gives its WS and BS to a unit of Warriors? Yes please! The price increase will be seen, especially if you want to field minimum groups of Termagants to get access to the big guys. A Tyranid warrior, in my opinion, is not a shooty model. It needs to be in close combat, and giving up your run to shoot will not get it where it wants to be. Even being BS4 from the Prime, Warriors have access to at best 3 shots that will glance off a marine. If I was to take a Prime HQ for a shooty army I would probably put it into a unit of Carnies, give it a pinning cannon and watch things die while being guarded by the big boys. Slapping on the extra 6" Synapse and you can essentially keep all your models together as they march across the field.
TROOPS
Termagants - These guys are the best meat shields you will field in your shooty army. At such a low point cost, it frees up the rest of your army. I would not take just 10 though, not when a unit of Marines can do 10-20 shots. You want at least 15-20 per unit to use as bait. Give your big guys cover while marching down the fields! Don't forget they still have good close range weapons, being S4 they can still hurt marines with a large amount of fire-power.
Warriors - Like I said under the prime, these guys aren't made for shooting (IMO). Coming stock with a gun is nice for special occasions but giving up a run to shoot almost feels like a waste. Since Warriors haven't changed in the slightest since last book I have a couple years with them to test LOL. Every game that I tried them as shooty they did okay, by okay it was mostly getting them into cover to help with the AP 4 or better weapons while trying to take out squads and pinning things. I would suggest always grab the Barbed Strangler, the pinning large blast in my opinion over-weighs the small blast, larger strength venom cannon. Being able to shoot before an assault is nice, and only in those occasions would I ever shoot, but to give up that run hurts a model that NEEDS to be in melee. I only ever run these guys as melee bugs now, equipping them with swords and whips and now flesh hooks. If you want me to go into detail about how to maximize your Warriors in an all melee army I'm your man

(includes Steals too which people say suck but I always get them to perform awesome).
ELITES
Here is where you have some really good options for a shooty army.
Zoanthropes - BS4, Synapse, access to the best anti-tank/anti-marine psyker power, our only invul save (out of CC). These guys have dropped in price.. by a lot... and with the addition special rule of brotherhood of Psykers these guys have risen to being in my army in every single list. Not having to roll LD for each Zoa is awesome, yes the downfall is if you fail they all fail but at LD 10 you should hardly ever fail. A single Deny the Witch can be made true, but it's still that 1/6 chance. Being able to choose what arsenal they want to shoot out AND having another power if they are too far away is awesome. Giving FnP to itself and a unit close by will make marching up the table that much more easy. I would take at minimum 2 of these bad boys, but 3 maximizes the amount of damage that can be done (obviously).
Venomthropes - My god these guys have gotten better. They are almost an auto-include now. I used to anger myself trying to find a way to include them in my army since they are awesome looking models but the 5+ cover with the price tag just wasn't that great. Not when there were other things I could take for Elites. Now, with being 10 points cheaper and the new specal rule giving Shroud rather than a 5+ they have gotten fricken sweet! Grab 3 of these guys, place them in a triangle to maximize unit coherency and you essentially have a 15" bubble of shroud. Stick your big guys so even a piece of their base is in the 6" and they can gain a cover save against those pesky Ap2/3 shots while they travel across the board. Get the big guys into cover and watch that 5+ become a 3+! if you want to maximize your efficiency of shooting, you will want to invest in a Venomthrope Brood, they have gotten very good. Abeit not very shooty themselves lol.
Hive Guard - I am sad, losing 1 BS and getting more expensive hurt. Especially since they were our best anti-tank options. However, getting a Haywire gun that uses a blast template is... not bad.. I feel you won't be seeing very many of these guys any more, not when there are better options out there. They still work well, and are still one of better anti-tank bugs but at the price tag and loss of BS they are not my anti-tank bugs any more. I used to love these guys, and I'll admit, they are still our best chance of anti-tank shooting we have. It just hurts losing 1 BS and a price increase.
Pyrovore - Another model that is confusing. These bugs got a slight decrease in points with literally no other change except a special rule that currently has the interwebz in such a hysteria. It's also personally the worst looking model in terms of... well... anyone can clearly see the resemblance in the model. I have tried this guy before, I actually have a model of him chilling in my basement. His stat line is not bad, essentially a Warrior that is slower, has less attacks and is dumb. People usually label the Pyrovore as the bug that doesn't know what it wants... and it's true. It has the capabilities to be a good melee bug, but lacks the Init or attacks. It has the capability to be a decent shooter.. but lacks any real motivation or range to do so. Not a favourite of mine, however I might not have learnt how to maximize his effectiveness yet.
FAST ATTACK
Shrikes - Same deal as Warriors. The advantage is they have wings... but they have an even worse save that bolters will destroy. Personally not the best effectiveness by giving them shooting weapons.
Raveners - I am kind of bias towards these guys. They have one of the coolest looking models and are beasts! Giving them devourers is a double edged sword. You can move 12" sure, you can shoot 18" sure, but your save and urge to feed (get into melee) out-weighs it all too greatly. I would rather equip them with rending claws and go tank hunting. I have taken Raveners with Devourers before and have done well, one game I shot a unit of marines before assaulting and ended up killing two... and then finding out that my assault roll would've landed if those two marines were still there! personally not a shooty bug, although they do have the potential for shooting in special circumstances and should not be warranted out entirely.
Gargoyles - These guys are the coolest flyers you'll ever have for such a low point cost. They can keep up with Flyrants giving them cover saves and dish out some decent damage. Losing the auto-wound of a to hit roll of a 6 hurt, but at least they have poison 6 (in cc)! I would take these guys if you want some cover for your Flyrant, Harpy or Hive Crone, otherwise leave them out to get more points in the other categories. They are more a close combat unit than a shooty unit however they do still do well for their points. Tell you the truth, they are the perfect side kick to a Harpy.
Harpy - Oh harpy, how thy model makes me smile. This model is probably the biggest want of a Tyranid player and man did GW give us a beaut. HUGE point drop, for pretty much the same bug we have always enjoyed with an additional wound and attack. This bug can lay down barrage mines in the movement phase, pin guys in the shooting phase and then eat them up in the assault phase! It's screech is awesome. This bug has to be one of the best well rounded bugs we have. It's armour save is meh, but at least it has an armour save and a further jinx save if diving. If you have the cash to pick one of these up, you won't be disappointed. Plus, combine it with a Flyrant (both shooting and melee) and anything you target will be gone.
Hive Crone - Ah, our first new bug! At first glance it whispers Harpy brother, then after reading, it screams anti-flyer! Tentaclids are awesome bug missiles that have haywire and the ability to reroll to hit vs Zooming Flyers and Swooping Monstrous Creatures. It's drool cannon is not bad against ground targets and it's special rule allows it to have a high strength vector strike attack. Helldrake bug anyone? It even has a similar appearance. It's price tag is more than a Harpy but it's anti-Flyer payload is definitely hard to pass. If you find yourself facing Flyer lists I would suggest taking a Hive-Crone.
HEAVY
Carnifex - I love these guys. Although I take them melee, they have great potential as shooters. Take two Twin-Linked Devourers and watch things die like they did last edition... but doing so cheaper! They got a HUGE point decrease and I feel they will be seen even more in lists now. Pop in the prime and you have a walking squad of death, add the Venomthrope and they are almost untouchable (unless your stupid tau). Even if they assault into close combat they are going to kill pretty much anything the unit has without needing close combat weapons. I have 5 of these guys, they will be seeing more playtime now due to their price drop and I can only imagine people will be fielding them as Dakka-Fexes like always.
Biovores - These guys got slightly cheaper and give the same as they did before. Barrage shots with 48", sniping models and making your opponent angry (that was a good game

). These guys are good for support fire, but with the point decrease of Carnies, the addition of new bugs and the over all better choices elsewhere I feel my 3 Biovores will stay on the shelf more games than nought. Not saying they suck, because they don't, I just have other options now. Having LD 6 and needing Synapse to keep them shooting is too much when I can march across the field laying waste to my opponent!
Exocrine - One awesome shooty bug that is full of awesomeness. This bug is a Marine killer, heck this bug is a Terminator killer, or even a Monstrous Creature killer! Being able to shoot two different profiles of guns is awesome. Whether you have single targets or a whole squad anything can be done to kill your foe. It has high strength and AP 2, definitely going to see things fall. Stream profile is a monstrous creature killer while the blast is an infantry killer. Either way, this bug is worth the price tag and if your going for a shooty army he/she/whatever you want to call it will fit nicely. It's special rule is kind of worthless if your constantly moving, however once you get into a good position let it sit and gain that bonus! It's statline is impressive, definitely going to make your opponents hate it and will be the target of all their AP2/3 guns so make sure you have that shroud from the Venomthrope or the little bugs.
T-rex - HUGE point drop, same big beast as always. Also our only natural 2+ save bug. This guy I like, especially having an assault 20 bug that can also get Thorax and has a Stinger Salvo. Things are going to die from this guy, and the price tag is, IMO, well worth it. I had this bad boy take out a full squad of Marines once and then had to sit there because there was nothing to assault! If the beast had BS4 this thing would be the most broken, auto-include bug in a Tyranid Army. I am happy the price tag has been lowered, before it was hard to dish out that many points, but now I feel more comfortable. The T-rex also has a really good s10 gun that WILL take out tanks. Not the greatest use of a bug that should be in your face however I have taken out a raider with it before.
Overall, the Tyranid codex has some really good shooting bugs. To recap, the ones I would most likely field in a shooty army would be:
Flyrant with Devourers (dependant on points and opponent)
Prime with Synapse relic and Cannon
2-4 Termagant Broods x15-20 for meat shields, minimum troop and general shooting. If you are playing a objective heavy game I would then advise taking larger units.
1-2 Zoanthrope Broods for Synapse support and anti-tank/infantry
Venomthrope Brood for shroud
Harpy for a mixed bug that can help against those pesky units in the back or to tag-team stubborn units that get too close.
1-2 Hive Crone for Anti-Flyer
1-2 Carnie brood with two Twin-Linked Devourers
Exocrine for the infantry/Terminator/monstrous creature killer
T-rex for the in your face bug
Hope that helps your decisions, like I said I usually play melee lists but those are my own personal findings for the new codex along with some personal bias lol