Ok, ok, it took us a little longer than we expected, but we finally got the ASP.NET 3.5 Extension Preview posted! This is the release with all the MVC goodness you have been hearing about as well as some very cool stuff such as Dynamic Data controls which makes building data driven web applications a breeze, AJAX history support, ADO.NET Data Services (aka Astoria), the ADO.NET Entity Framework and updated ASP.NET support for Silverlight.
Download the bits - they work with VS 2008 and are side-by-side so they will not hork your system
Check out the Quick Starts
Get Involved in the Forums
Here are a few links to get you going: