[shaun_amos]

I know that with IOS 4.0 you can load wads directly from the SD card but, is it possible to do this on 3.3 with any sort of homebrew?

[weswii]

You mean actually install the channel on the SD card and have it show up in your channels menu? No, I don't believe you can do that. Obviously you can install from the SD via homebrew, but the channel would have to be installed on the Wii itself. Even with 4.0 I don't believe you can run channels from SD that you haven't actually purchased.