This modchip allows the wii to run homebrew code as well as many other things, such as:
Wii originals
Wii original imports (partial support)
Wii backups
Wii backup imports (partial support)
Gamecube originals
Gamecube original imports (partial support)
Gamecube backups
Gamecube backup imports (partial support)
Gamecube homebrew
All medias (DVD-R, DVD-RW, DVD+R, DVD+RW)
Dual Layer support
Fully configurable speed setting
Automatic region detection
Stealth (well, at least as much "stealth" as any other Wii modchip currently available)
"Safe" Configuration disc
Optional status LED
Optional disable switch (solder wire to reset switch)
GameID overriding for some GameID's that was blocked by firmware 3.0
Support for Super Mario Galaxy backups