I'd lean towards the Viera as well, but I think two races with animal features is enough for now. But if I had to guess, I'd say the Viera are the most likely choice for the next race we get.

I also doubt square enix will go too outlandish with appearances, I doubt we'll see any monstrous races of any kind, but I'd want something like that. The Burmecians from FF9, the Garif from FF12, the Bangaa from FF12... you get the idea.