the xbox 360 creators club is up and running. this option allows game developers to use the XNA game development platform to create and run xbox 360 games.
although the game studio express (GSE) dev environment is free, the creators club requires an xbox live subscription and a creators club membership.
refer to the XNA blog (and the GSE docs) for details about setup. once you have everything installed, you can connect your xbox 360 to your pc and begin to work your magic.
this screenshot shows an xbox 360 project deployed and running on an xbox 360. the project is running in debug mode and a breakpoint has been hit - all while still listening to the iPod connected to the 360... nice.
- debugging an xbox 360 project - click for full-size version