The cat has left the bag, hopped on a train and skipped town. News on how to exploit an integer underflow bug in the security routines of the Xbox dashboard's font loader have been posted at Full Disclosure.
The example code there does NOT, repeat NOT allow for copying games or playing copied games. Full Disclosure isn't going to help you do that, and neither is Rampancy.
What this news does do is usher in an era when Xbox Live gamers may have to worry about the same kind of cheating that PC gamers do, and Microsoft is going to have to seriously start worrying about software piracy on its subsidized gaming hardware. Oh, and Linux computing, too.