Thanks to the release of the source code of the Twilight Hack, has been found another bug, this time in Super Mario Galaxy!
The video shows that, by going in a determinate area, the game will crash and will be run the installation of the Homebrew Channel.
Unfortunately, you must perform a glitch to make the buffer overflow happen, and this is not easy at all (Video)
As you can see, you have to "get stuck" in the planet.
Moreover, as in Zelda Twilight Princess, the savegame data must be replaced with an hacked one, and it won't be possible to use it for playing
It's way better to use the Super Smash Bros exploit, or the easy Bannerbomb
For proving the authenticity of this exploit, has been recorded another video, to prove that is not fake:
http://www.youtube.com/watch?v=_0HknevDYkE