I think playing as birds or horses would be a hit for a LOT of people, though I like to play as only canines and felines. However, making more options for markings, ears, tails etc would be great. That along would give us more options for feline and canine species.
When I think of Wolves, felines AND other things like dragons, owls, deer and etc I think of Arokai or what ever. Which sounds awesome, but you know. I would personally go with adding anything. The more options the better, but if not that's fine.