The BioWF project is a recreation of the Trident Scientific Workbench from MSR but using Windows Workflow 4.5 and .NET Bio 1.1. It allows you to create programs visually by connecting various components together in the designer and then persist them to an XML file which can either be run in the GUI designer, or from a command line tool.
Check out http://julmar.com/blog/mark/?p=323 for a very simple example of how to use it.
BioWF was created by Mark Smith (@markjulmar) and is completely open-source and published under the Apache 2.0 open source license.
Contact Mark Smith - email@example.com with questions or to become a contributor.