I just read on a blog that the latest service pack update to Vista may bring your pc to its knees. If you have an option, you might not want to let it update.
What surprises the hell out of me is why this Microsoft hasn't totally recalled Vista. Once a lemon, always a lemon. You can make all the lemonade you want, it will never be apple juice. One decent thing that they did was, I think, is keep XP around so those fed up with Vista can reload XP.