The "only" problems I've had with Vista is intermittent crashing. Don;t ask me why, but this bugger just LOVES to crash. Especially when shutting down, going to sleep, hibernating, and watching videos in a web browser...(In all cases, it doesn't do it ALL the time, just more than it should)
Other than that, the search feature is light-years ahead of XP, the presentation is awesome (love the transparency :D), and the error messages are a lot more likely to actually tell you what the heck is going on. So I'm not too teary-eyed to see XP go.
Not trying to be a fanboy. Of course, it's hard when you own the best console eve... dang it