I couldn't leave this one alone.  While I was making the last episode I said that there was possibly another strategy for detecting states and transitions and that was to use Tracking data.  In this episode I'll show you a better way to implement our WPF UI using the Model View View-Model (MVVM) pattern that does not require the state machine to have actvitivities to notify the model of state changes.  The source including some really cool unit tests that make use of Microsoft.Activities.UnitTesting is available here.

Ron Jacobs
http://blogs.msdn.com/rjacobs
@ronljacobs