Microsoft released XNA Game Studio 3.0 today in conjunction with its Xbox Live Community Games Channel.
The XNA Game Studio 3.0 is a .NET game framework that works with Visual Studio 2008 and is designed to allow the creation of cross-platform games.
Developers can create games for the PC and Zune platforms for free and with a paid XNA Creators Club membership develop for the Xbox 360 and submit their Xbox 360 games to peer review. Approved games are listed for sale online in the Xbox Live Community Games Channel with the proceeds split between Microsoft and the developer. Microsoft has approved three pricing points, 200, 400, or 800 Microsoft points (US$2.50, $5, and $10).
Wired has a look at the first few games approved.