I just came across this update to the .NET 3.5 Enhancements Training Kit from Jonathan Carter.  If you've seen my ASP.NET 3.5 Extensions Preview webcast and are looking for the code, then you will want to download the kit.  I used the kit as the starting point for my demos.  I do a few things differently here and there, but most of it is because I didn't have time to show everything in 90 minutes.  As far as I can tell, everything that was in the extensions preview is in 3.5 SP1 except ASP.NET MVC which will be shipped separately.  The training kit offers a great way to get your hands dirty with the new stuff in 3.5 SP1.  Go get it!  Oh yea, I have also updated the deck from my webcast to reflect the changes.  I have also added a couple slides about what's new in WPF & WCF.  You can download my new 3.5 SP1 deck here.