I don't play 'nids, but my main opponent does, and I've played against enough lists to have a pretty good idea how they work.
For your HQs, I'd lose the Tervigon. In 5th, they were practically a must-have, and the ability to have a scoring monstrous creature in 6th was quite valuable, but in 7th, it almost doesn't matter. Objective Secured is nice, but you hardly need it to win, and if you're scoring with MCs, there are better options than a Tervigon. For example, a second Flyrant. I'd set up both with two brainleech devourers, though - you want the dakka, trust me. That much on a flying MC platform with a vector strike and maybe psychic shooting is really scary to anything that's not T8 or AV13, and you have enough weight of fire to even hurt the various T8 critters. Plus, with Smash, you don't need the scything talons to be effective in melee. It's not as good as a lashwhip/bonesword combo, but Hive Tyrants are terrifying melee engines even without it. You can forego Hive Commander on the second Flyrant if you want, and I'd probably pass on Regeneration.
I want to like the Haruspex, too, but I've only taken serious damage from one in a single game. Admittedly, I play Tau and Eldar, and both are scary opponents for Tyranids, but the 'spex is just a wee bit lackluster. It eats tanks for lunch, but so do Carnifexes. Lose it, and add a third Hive Guard. Also, while you're looking at Elites - Venomthropes! You want them, if you ever see shooty opponents with good AP (like Tau, or Eldar!). Two singletons, or maybe even two pair. You want two singletons rather than a brood of two so you can space them widely, covering more of your army, and not lose both to one unlucky large volley.
For your troops: I can't complain too much but I have some pointers. Genestealers are better than the general opinion says, I think, except against scary-fast melee units (Dark Eldar, some Daemons). But, it's all dependent on where you can infiltrate them. If you're going first, they stink except as a dangerous decoy. Hormagaunts work well, in my experience. That brood you've got isn't bad, though you could probably use toxin sacs if you expect to see much T5+, but make sure to keep 'em in synapse. But, with two Flyrants, a squad of Warriors and a squad of Shrikes, you should be good.
Termagants - not bad, not bad at all. I like the squads a little bigger, but that's not bad. Devourers are pricey but nice, however, don't rule out the good old spinefist. It looks sucky, but the fact that it's twin-linked is surprisingly handy, especially in larger broods. Maybe if you can spare the points, do two broods of 20, one with 5x devourer and 15x fleshborer, the other with 5x devourer and 15x spinefist. Spike rifles, of course, are a total waste of time.
Warriors - Good, though a barbed strangler would help and it's hard to go wrong with rending claws.
I'd drop the Regen on the Crone. Chances are the Crone will either be focused down in one turn or will hang around mostly unmolested all game, regardless. Also, there's nothing quite so frustrating as having it grounded by a volley of Smart Missiles from a Riptide, and then one-shotted by a Hammerhead or a Wraithknight. (Though, admittedly, the changes to grounding in 7th make this much less of a threat.)
Shrikes are hard to go wrong with, though I like giving at least one a lashwhip+bonesword and rending claws for the rest. Don't forget, on the turn you plan to charge, don't use the jump move so that you get your Hammer of Wrath attacks. May not seem like much, but every attack adds up. Also, while you'd have to take two combined arms detachments to do it, Raveners are *very* nasty, and Shrikes team up very well with them. Move the two together, then fork off at the last minute and hit separate targets, if there are several. If not, dive in and rip apart a large squad with reckless abandon. Deathspitters are mostly a waste of points, though, so if you take Raveners, give 'em spinefists. (Devourers are OK, but spinefists get the same number of shots on a Ravener, get some AP, and are twin-linked. The extra strength isn't worth much.)
I'll second everyone else's recommendations on the 'fexes - lose the tail and the regen, pick up the dakka. Take two in a brood, give one 2x devourers, the other devs and crushing claws, if you expect to see a lot of AV14. Otherwise, go dakka all the way, and Smash if you really need to.
One unit you might consider is the Exocrine. Don't worry too much about the rather lackluster blast mode, instead, focus on the streams attack. That's your tool for bringing down the big, tough units in shooting (like Riptides). If you rely on assault to kill them - and an opponent figures that out - he can easily kite you all over the board, doing massive damage along the way, so bring along an AP2 shooting threat.