So far, I've been really impressed with the two Non-human Races shown so far. I'm not a greenskin player, but that Orc just struck a chord with me. Because of the product penetration with WoW, Orcs tend to look way too silly, almost like an army of Shreks. I'm glad to see something so ferocious and different, yet down-to-Earth (Nirn?).
Khajiit, I would need to see the whole body, including the legs, I was always fond of the reverse jointed Khajiit from Morrowind, though not so much their faces.
They aren't reversed joints (at least in real life, I don't remember the Morrowind ones off hand). The knee is just extremely far up, and the "backwards" joint isn't backwards at all... it's the ankle. Cats and many other animals walk tip toe. I'm not a fan of the look, but if they do it, a backwards knee isn't what happens anatomically.
See:
http://www.pictures-of-kittens-and-cats.com/images/cat-skeleton.jpg
Notice that cats don't actually have backwards knees at all. Their knees are just very high up.
Certaintly
because it's Skyrim!
I suppose they could just say fur color changes with climate if they wanted to, but the Khajiit aren't wild animals so there wouldn't be snow leopard variants in that way. I would expect fluffier fur during winter though as happens with real cats.