This is somewhat older news but I think it's fair to point out how far along the wii homebrew scene has come along .The latest exploit allows those with the Zelda Twilight Princess game (such as myself) to be able to run roms from other systems via a built-in wii channel. This hack thus does away with the previous method requiring homebrewers to insert the game disc each time they wanted to use homebrew.
For more info, please see http://hbc.hackmii.com.
DOWNLOAD HOMEBREW CHANNEL HERE
Update (8/21/08): Click here for a Lifehacker how-to article on how to hack your wii to play dvds/play homebrew. It's ridiculously easy to set-up and foolproof. Just remember to have a compatible Zelda game disk and an SD storage card formated to FAT-16. I've already hacked my Wii. The homebrew channel is amazing but what's more amazing is the homebrew browser that lets you download a continuously updated stream of homebrew applications (like Dragon Media player and Mplayer for DVDs and Mp3/Ogg playback), utilities, games (like Quake and Duck Hunt), and other stuff (ftp servers, etc.) Definitely worth the try.