Several people have asked me about the managed Space Invaders demo, as well as where they can get the code for the Add/RemovePressure demos that the CLR team showed while in Atlanta.  You can find these demos as well as several others online:

http://msdn.microsoft.com/netframework/downloads/samples/vs2005/

Now if I can figure out where to get the serial device that Kit George was using, I would be golden for the upcoming .NET Developer Experience Expo in Atlanta :)