I want animals that fit Skyrim.
I'm thinking big furry animals... and huge aquatic animals.
And some skinny malnourished animals in caves (sorta like hungers, but obviously more original).
They really have a lot of potential wish Skyrim. They could go above and beyond with the creatures there to make them interesting.
Skyrim lake vampires. 'nuff said.
But yeah, I really want Bethesda to look at real life examples for inspiration*. Just look at wildlife found around the north of the world, throughout history. And everything around the Ice Age. I'd love to see Bethesda's take on Mammoths, or even Penguins. there is, as you've said, a lot of potential in Skyrim (not that there isn't in the other provinces, though).
*inspiration doesn't mean direct copying. I want originality, not something I've seen a million times over.
The below statement is most un-Hircine-ey thing ever. Don't read it if you don't like to tarnish the reputation of Daedric Princes
And I really want to see better aquatic animals. Is it just me, or is the sea a naturally scary place, for us land mammals? I know that I, personally, would be scared to death if I was near an Orca, or even a Blue Whale, even though it would never hurt me. I want that same feeling in TESV. Aquatic animals should prove to be quite the challenge for even high levels. though, they should only be found out in the wilderness, where nothing would probably be. I don't want to be swimming through a lake on my level 1 character, and be eaten by a giant whale creature.