BPEL for WF is available for download at Microsoft Portal. BPEL is the standard execution language used to specify the workflow of Web Services. It sits on top of WS Architecture, and allows the orchestration of Web Services supporting business processes.
You can find several realization of BPEL in products such as Oracle SOA Suite, and Microsoft Biztalk Server 2006.
Now you can import/export BPEL orchestrations into WF.
Enjoy it.