castlezelda a buddy of mine just hooked me up with the homebrew channel ,and im 4.2u firmware so i could help ya. I want to make something clear though that confused me at first.
While yes using Homebrew Channel you can make means to get emulators to play roms of old systems. You can not however play pirated retail games with the homebrew channel unless you go through the means of softmodding through applications that you can download with the homebrew channel.
I didnt go this route though as A) Wii devs need all the support they can get & B) there are too many conflicting tuts on how to do it which makes it way too risky.