I've always wanted a cat mount (I'm undead) because I think that their model is really cool looking. I grinded to Exalted with Orgrimmar so I could get a Wolf (I hate the color of the AV one. That and everyone and their brother has one) because they're the closest thing and are pretty cool in and of themselves. With the addition of TBC and Horde getting Blood Elves I finally had a glimmer of hope (Other than hoping to win a rare drop in ZG) of getting a kitty! Lo and behold...
http://www.wowwiki.com/Cockatrice
And for those of you on easy-mode...
http://www.wowwiki.com/Elekk
I haven't seen models yet (wowwiki discourages Alpha images or something), but I'm imagining Cockatrices will look something like a raptorish Mechanostrider and Elekks will look something like a squashed Kodo with horns. I was pretty sad that we wouldn't have a chance at cat mounts :( At least I don't feel compelled to grind BE quests and give them oodles of potential bandages like I did with my Wolf (<3).
A buddy of mine was talking about the Winterspring mount which only Alliance have access to, but I wasn't terribly impressed. It looks like that big purplish cat that every other Hunter seems to have. I saw an article about a potential raptor you can get in Un'Goro but I didn't see anything about faction, though I'm sure it will need Darkspear rep in addition to w/e(For the Winterspring mount you need Tiger riding skill).
That said, what is your favorite mount and will you try to go for these new additons (Provided you don't roll Draeni/BE)?
... That is if you waste your time/gold on these kinds of things :P What can I say, it keeps the game "fun".