Building killer Games using .NET and XNA Game Studio Express
XNA relies on a version of the .NET Compact Framework CLR that we ported to run on PowerPC chips (the XBOX 360 ships with a 3-core PowerPC CPU). For a killer demo that will impress your friends, install XNA Express, load up the built-in "SpaceWar" C# starter kit template, customize it, deploy it to the XBOX 360, run it and dazzle them with the graphics, and then set a breakpoint within your C# code in Visual Studio and show hitting the breakpoint and stepping through it in a live debug session against the XBOX 360 as you are playing the game. Pretty cool.
Game development in managed C# this is cool, you no longer have to be a C++ developer to create games.
XNA on MSDN
XNA Development
XNA on Channel9 The Best XNA Movie in the UNIVERSE