The BPI Dev Center is up:

New on MSDN (okay, recently added to MSDN -- I'm behind in my blogging) is the Business Process and Integration Developer Center. Lots of info for developers working with Biztalk and other server products. If you're interested in server-side development and you don't think BizTalk is real programming, you just don't get it.

Set yourself free:
http://msdn.microsoft.com/bpi/