As you might have noticed, WinFX recently became .Net 3.0 [1]. They set up a nice community site at [2], this is also where the WF now resides [3].
At [4] you can find a comprehensive overview of blogs related to the WF, aggregating blogs of the WF team members at Microsoft together with community blogs. That’s really great, ’cause now subscribing to one single newsfeed keeps you up to date.
Thanks for the link!

[1] Welcome to NetFx3.com
[2] Microsoft .NET Framework 3.0 Community (NetFx3)
[3] Windows Workflow Foundation
[4] WF related blogs