Blend 3 and SketchFlow are out and let me tell you they ROCK…. here are some good links on this subject
Behaviors
http://electricbeach.org/?p=171
List of Behaviors from the Expression Blend website
http://gallery.expression.microsoft.com/en-us/site/search?f[0].Type=RootCategory&f[0].Value=behaviors
Demo of Blend 3 and SketchFlow
http://msdn.microsoft.com/en-gb/ee341352.aspx
Videos on Sketchflow
http://www.microsoft.com/belux/MSDN/nl/chopsticks/default.aspx?id=1325
Blend 3 list of new features
http://blogs.msdn.com/expression/archive/2009/07/12/overview-of-new-features-in-expression-blend-3-sketchflow-part-iii.aspx
http://geekswithblogs.net/tkokke/archive/2009/07/10/9-little-new-things-in-expression-blend-3.aspx