WinFX Documentation is online now and includes Windows Workflow Foundation.  This is for Beta 1 of Windows Workflow Foundation which requires Beta 2 of Visual Studio 2005.  I created this little blog entry that links to all the workflow sections in the WinFX docs.

Windows Workflow Foundation Windows Workflow Foundation Overview Windows Workflow Foundation Programming Guide Windows Workflow Foundation Tutorials Class Library Reference System.Workflow.Activities System.Workflow.Activities.Rules System.Workflow.Activities.Rules.Design System.Workflow.Activities.Rules.Design.CustomTreeView System.Workflow.ComponentModel System.Workflow.ComponentModel.Compiler System.Workflow.ComponentModel.Design System.Workflow.ComponentModel.Serialization System.Workflow.Runtime System.Workflow.Runtime.Configuration System.Workflow.Runtime.Hosting System.Workflow.Runtime.Hosting.Web System.Workflow.Runtime.Messaging