My pet findings: (Spec 51/10/0)
Core Hound (specimen - The Kurken, renamed Hades)
Advantages: Looks cool when standing still, Lava Breath is good
Disadvantages: Animations are somewhat limited or simply look crap on this scaled down tamed version, ground shake
Status: Still stabled
Devilsaur (Specimen - white one from Un'Goro, still unnamed)
Advantages: great fight animations, blood drips from mouth after Monstrous Bite, Monstrous Bite is awesome
Disadvantage: Limited selection meaning you see loads of pets the same as yours, the ground pound is a little excessive considering how small they are now, plus I see my Hunter as a stealthy sort, so the Devilsaur is a bad fit aesthetically.
Status: Released
Silithid (Specimens - rare tan spawn in 1k needles, and blue one from Tanaris renamed Yautja)
Advantages: Venom Web Spray is is the best exotic skill I've seen yet! great fun to play with
Disadvantages: Limited animation, it does the twitchy thing too much, lack of personality
Status: Released (may possibly get another one)
Wasp (Specimen - Blacksting, renamed Dart
Advantages: Sting is very good in both PvE and PvP
Disadvantages: Kinda boring to look at, same problem as Silithid re: personality
Status: Released
Chimera (Specimen - Green one from BEM. Gave up on Nuramoc)
Advantages: Very strong special attack, looks quite good when fighting
Disadvantages: Wings continually clip through the player when standing still, not evough variety meaning everyone either has the same one I had, or a lucky few with nuramoc.
Status: Released
Moth (Specimen - Green glowy one from Terrokar, renamed Acherontia)
Advantages: Good special when it's up, the one I had particularly had a quirk where it kept the green glow after taming making it stand out among the others who all picked the blue one, not a particularly popular pet so you don't see many.
Disadvantages: Reason it's not popular is because it's a moth! Cooldown on special is quite long, I really wanted to like this pet but I can't seriously have one on my Troll, it just doesnt feel right. Maybe if I was a Night Elf.
Status: Stabled
Cat (Specimens - Ghost Saber renamed Zhora, Humar renamed Midnight)
Advantages: Looks cool, good fighting animations, prowl is now a bonus toy rather than a gimped special, rake is actually pretty good
Disadvantages: Why didnt they pick a better model for the Ghost Saber? I like the translucency but hate that cross eyed face most cats have, cats are pretty common
Status: Zhora released, Midnight promoted to main pet.
Conclusion: Cat FTW! It's only really unusual for me as I've never had a cat as my main in all my time as a Hunter, as I mentioned earlier, I hate the skin on most and couldnt be bothered to level the ones I did like, so I abused the pet autolevelling system. I realise black lions will be 10 a penny once more Hunters see the new one in Northrend, but it doesn't particularly bother me currently. I have a pet I like to see standing beside my Hunter and he's effective DPS. I will probably grab an eagle once I can though as I've always wanted one.