What’s the point of the Sidebar in Windows Vista?

At PDC, the Sidebar took a new focus, as it was announced that the new “Gadgets” platform would be compatible with the Sidebar, allowing Gadgets to be docked?

Given that the Gadgets can run on the desktop, what’s the point of “docking” them on the Sidebar, unless you’re going to hide that Sidebar anyway, defeating the purpose?

It really seems like the Sidebar is an answer looking for a question.  I used the MSN one for about a week before turning it off, and the Google one lasted less than a day.  It just takes up too much screen space.  I use Konfabulator widgets on my work desktop, but not on my Tablet since the changing from Landscape to Portrait moves them around.

Someone answer me this.  What is the Sidebar supposed to do that isn’t already being done by the Task Bar, Desktop, or some other technology already in Windows?