This is the source code for the two chat samples presented by Stefan Schackow at the BUILD 2011 conference. A video of the presentation is available here: http://channel9.msdn.com/Events/BUILD/BUILD2011/SAC-807T
To be able to compile and run you will need the Windows 8 developer preview available here: http://msdn.microsoft.com/en-us/windows/apps/br229516