We had a workgroup about BPM on the Microsoft platform last week here at Dolmen. One of the topics which came up was the use of BPEL (Business Process Execution Language) and BPMN (Business Process Modeling Notation).
So it's great to see that Microsoft will add support for BPEL in Workflow Foundation with a CTP release in march which will implement the BPEL 1.1 specification and ). The final release will also support BPEL 2.0 and is planned for Q4 of 2007. (Sources : ITWorld and Paul Andrew's blog).
I actually taught that BPEL support would have been availabe with the RTM version of Workflow Foundation since it was already mentionned during the beta phases. Take a look at Introducing Microsoft Windows Workflow Foundation - an early look from august 2005 for example which stated
For developers who wish to use BPEL, Windows Workflow Foundation includes a BPEL Activity Library that implements the constructs defined by version 1.1 of the BPEL specification. Using this library, it's possible to create workflows that can be exported to BPEL, or to import a BPEL definition into Windows Workflow Foundation.
David Chappel adds some interesting information as well ...
Similarly, any imported BPEL workflows will be converted into WF's internal representation. Like BizTalk Server today, WF treats BPEL as a way to move process logic between different workflow engines, not as an executable format (and certainly not as a development language)
This is similar to the way that Biztalk uses BPEL. I think that Oracle BPEL Process manager is currently the only tool which really embraces the concept of BPEL for defining processes and workflows.