Robert Scoble has posted video on Channel 9:

"Sidebar lives!

But it's even better, here
Sean Alexander, David Streams, and special guest Sanaz Ahari of the Start.com team, demonstrate the new sidebar and gadgets that come in Windows Vista. Plus, we cover the three different kinds of gadgets and show how to build your own.

You can learn more on the
Microsoft Gadget site."

Also, check out Windows Sidebar blogger is Shawn Morrissey:

"The folks on the team have been bouncing up and down, waiting for Bill to show off one of the projects our team has been working on – yep, it’s the Windows Sidebar…  It’s baaaaack… "