It isn't unbalanced at all. I can see BM hunters being welcomed into raids with a core hound for this reason, especially if there's no shaman in the group already. For a while into the Beta I was really starting to frown at the hunter changes, but now I think they're started to look wonderful. Perhaps BM hunters won't be so bad anymore.
And now I think Archaeology (Need to think of a short way to write this.) looks really exciting! Can't wait for Cata.
Now why would you want that? Both the Celestial Steed and Invincible (Currently the only two horse mounts in the game with the same model.) look awkward and somewhat silly. Invincible less so than the Celestial Steed, but even so, they look strange and more like a pony than a horse. I'd like to see a revamped version of the original horse mounts.