In addition to the WinFX November CTP, Microsoft has released the Microsoft® Visual Studio® 2005 Extensions for Windows Workflow Foundation Beta 1.2 for Microsoft Pre-Release Software WinFX® Runtime Components - November Community Technology Preview (CTP).
The Visual Studio 2005 Extensions for Windows Workflow Foundation are required for customers who are designing workflows in Visual Studio 2005 and/or require the Windows Workflow Foundation SDK.