Looks like iTunes and Vista not wanting to play together goes deeper than we thought. Straight from iTunes tech support:
Apple recommends, however, that customers wait to upgrade Windows until after the next release of iTunes which will be available in the next few weeks.
You gotta love Apple telling you to hold off on updating your whole OS just for iTunes. UAC issues aside, you'd think if they had time to make that spot that's got Bill's blood boiling, they had time to get iTunes ready for the Vista launch.