A demo of Green Day: Rock Band is now available through the XBOX 360 Market Place. It contains two songs: 'Boulevard of Broken Dreams' and 'Welcome to Paradise'.

Watch 'Boulevard of Broken Dreams' video
Watch 'Welcome to Paradise' video

Click here to learn more about it.

The demo will be available to download from the PlayStation Network later today. No word on a demo for the Wii (though they often don't release demos released there).

Thanks to matteo263 for the heads up