Recently a screencast by Filipe Fortes has been making its way around Microsoft. Lots of great feedback so I thought I'd check it out.
Wow, what a great demo, it's well presented, very fluid, and it shows the power of the WPF platform.
Having written Photo and Video management/editing/viewing software in the past, I have a great appreciation for how easy WPF makes it to write media rich applications and Filipe shows it off brilliantly.
It's a great introduction to WPF, well worth the 20 minutes.