XboxSolution is reporting the same story as everyone else-- that a French language version of Halo 2 has hit the Internet. However, they've chosen to headline the story Halo 2 Source Code Leaked on the Web, which, as far as we know, is NOT true; Shishka's FAQ denies that anyone has broken into Bungie, and that the leaked copy is the binary version of the shipping game, most likely lifted from a manufacturing plant.
As depressing as the Halo 2 leak is, if the source code had been stolen it could potentially be worse, as it might open up opportunities for those with modded Xboxes to reverse engineer Halo 2's network play and create ways to cheat, which in many ways would be even less fun than finding unintended spoilers in Halo forums.