I haven't personally tried it, but i'm willing to bet you'd be better off staying with xp pro 64. Vista isn't going to make maya run any better, and most likely will slow it down unless you turn off all the areo stuff.
It's part of the process. Supposedly the technologies that MS introduced are quite cool, but it requires developers to re-code the apps to take advantage of it, which takes a while. Part of the breaks of the software lifecycle.