playing games off SD card would be painfully slow.... it might be alright for some of the VC games, but a real honest to goodness wii game would run like shit. way to slow. you really need some kind of fast access rates to play these games, like from optical or hard drives. personally im glad nintendo finally realized theres an internet. free demos a few console generations away for nintendo to catch up to lol.
for the record: i own a wii and 360