WiiToo! is a minimal precompiled stage4 made to let you run Gentoo on your Wii using MIKE and Mini. It provides all the basic software required to compile and install new programs on it, and some other software ready to be used. The kernel used is plain vanilla-sources & Wii-Linux patches, so expect WiFi working out of the box.

http://wiibrew.org/wiki/WiiToo!