In an earlier screencast, Henrik Nielsen illustrates how the Microsoft Robotics Studio, building on top of the CCR (Concurrency and Coordination Runtime) and DSS (Decentralized Software Services) technologies, exposes a RESTful service-oriented architecture.
In this companion screencast, Andreas Ulbrich demonstrates VPL (Visual Programming Language), a diagram-oriented dataflow language. Although it was created for the Robotics Studio, it is -- as you'll see here -- a very general way to visualize, orchestrate, and debug message-driven services that run work in parallel.