Vista needs permission for trivial stuff that the user already informs it that he/she wants to do. I had been using Vista on my friend's laptop for about half an hour, and I can tell you, I clicked "Continue" in the User Access Control dialog box at least 10 times.
On the contrary, Vista does not permission to do something that I DON'T want it to do! Like a restart after installation of updates. Vista can give you warning any time of the day that it's going to restart in 5 minutes, and it DOES NOT need your permission to restart. Microsoft already gave it the permission! You have no choice but to save your work and close all stuff and either wait for the stupid timer to complete or click "Restart Now". There is no way you can cancel the restarting!
For now, I'll stick to XP, which is so much more easier to use than this 'Wow' junk. I hate being interrupted by 'Wow' dialogs every 5 minutes, asking permission that's already given. And I even HATE to the max if 'Wow' force-restarts the computer without my permission or consent!