Eh?
They are not. Obviously, if you wish to play a teenage human female, I guess they are. Teenage girls usually have quite small hips.
On topic:
Possibly draenei. I can't really imagine how they could turn out. Any other race I can only imagine as an improvement. I think I read somewhere that the dwarf models look awesome according to Blizzard btw. I don't like them saying that, but hey, either way it is quite likely an improvement to what we have now.