Mostly, I dislike how they've re-organized most of the configuration screens, making it harder to reach the settings I change most often. I dislike the way everything is animated so that it slows down things that I want to do quickly. I dislike the way the new start menu looks and operates. And I don't like the phone-home mentality.

I think the only feature of XP that I really like is how quickly it boots up. That alone makes me *almost* want to switch to it.