Download migration documents from - http://www.microsoft.com/downloads/details.aspx?FamilyID=bd94c260-b5e0-4d12-93ec-53567505e685&displaylang=en

·         WF Migration Overview - Overview of the document collection and an initial starting place for the WF3 developer

·         WF Migration: Best Practices for WF3 Development - How to design WF3 artifacts so they are more easily migratable to WF4

·         WF Guidance: Rules - Discussion of how to bring rules-related investments forward into .NET 4

·         WF Guidance: State Machine - Discussion of WF4 control flow modeling in the absence of a StateMachine activity