Many thanks to Cyrus for pointing this out. Videos from the PDC are now available for streaming via http://microsoft.sitestream.com/PDC05/. The site is running rather slowly right now (it's not being Slashdotted, that's for sure,) so bring a bag of patience with you.
I, of course, recommend you start with Jeffrey and Jim's Monad presentation (during which I was Proctoring at the hands-on-labs.) As Jeffrey quotes, "This is not your Dad's filesystem". Then, if you haven't already, check out this year's belle of the ball, Linq :)
[Edit: Monad has now been renamed to Windows PowerShell. This script or discussion may require slight adjustments before it applies directly to newer builds.]