BPEL support for WF
Windows Workflow will be enhanced with extensions to support BPEL, a standard to create interoperable workflows:
http://blogs.msdn.com/pandrew/archive/2007/02/25/Microsoft-provides-BPEL-2.0-in-WF-_2D00_-BPEL-for-Windows-Workflow-Foundation-March-CTP.aspx
Note that this features (BPEL 2.0 support) will be incorporated in later versions of Biztalk.
