An early peek at Longhorn

The sidebar offers way to present certain kind of information and access. The widescreen argument is good, but if the intent is to show notifications of importance, its essential that user can pick the critical notifications (incoming call/important person instant messaging/mail from certain person) and get them shown during any moment, including playing movies, games, using VM full screen. In these cases the notification should arrive fading smoothly increasing opacity over time as to not distract movie or game with old fashion popup with junk information.

Also if you are playing a game, but there is a boring moment (waiting for multiplayer game to start etc), there should be something like the "new os x" feature, showing all the interesting "widgets", rss feed type of information overlayed on top of the full screen game when user feels like it. But possibly distracting stuff should not be enabled by default.

So essentially the side bar would just provide a feed of junk information. I'd much rather have tight user control over what information I think is of importance and have it shown any time anywhere. Sound notification in Star Trek computer voice is good alternative, but not until it sounds 100% like the Enterprise computer!