Watch this LINQ video

If you're at all interested LINQ, watch this video.

Even if you're not interested in LINQ, watch the video and you probably will be. 

This was Anders' presentation at MIX. It shows some very impressive capabilities of LINQ for XML queries which I plan to use in a few mashups soon.  This was one of the more difficult things to accomplish before (imagine a join across 2 XML documents) but has been made as trivial as a SQL statement.