AtomicPC writes hackers have found a way to run homebrew code on unmodified Wii consoles. The hackers claim they've found a bug in Zelda: Twilight Princess that enables you to run some arbitrary code from an SD card:
In the last 12 hours a major breakthrough has been made. ‘Hello World’ (or rather, ‘Hello Bushing’, a shout out to one of the hacking group’s members) was successfully being run and displayed. This is to date the first non-trivial piece of entirely custom code executed, running from an SD card and an original copy of Zelda. It may have been run on a modded Wii, but according to the hackers, it should also run on an un-modded Wii. The fact that this has been done means that homebrew isn’t just in the air. With this exploit, it exists, and with a bit of refinement it might even be user friendly.
You’re probably asking “What’s in it for me?” around about now. Well, at this stage, not an awful lot: these are still very early days reserved for the hardcore hackers. In the near future, however, as knowledge of the Wii system architecture starts to spread throughout the developer community, we will start to see some really cool programs.