We've just release the first update to our Pipeline Generator to Codeplex: https://www.codeplex.com/Release/ProjectReleases.aspx?ProjectName=clraddins&ReleaseId=9222
This release addresses many of the issues/suggestions the community filed with the first release. Additionally it adds support for defining structs in your contract assemblies. For some extensibility points structs will be an invaluable tool as they allow you to pass large amounts of data across the AppDomain/Process boundary much faster than you can with reference objects.
For a complete list of changes see the release notes in the linked project.