Here is the official word from Jeff Beehler, the Team System Chief of Staff, and the really official word from Soma.

Here is where you can download it from MSDN.

I have only been officially working on the Team System team for five-months, and I can say that I am thrilled about this release. I plan on releasing a lot of technical content about using Team System 2008. The sessions I have done in the past few months have been well received, and I would like to get the session content into an easy to share online format...perhaps a new ASP.NET+Silverlight application is in my future...using LINQ?

Now I just need to set up my new Team Foundation Server and get my work items entered and off I go :)