I just found out that the Wii's graphics shown at E3 weren't actually the Wii's. Instead, they were actually belonging to the GAMECUBE which is hooked up to a Wii Dev Kit. See for yourself!!
http://forums.nintendo.com/nintendo/board/message?board.id=revolution&message.id=1159528
The poster says that the ATI Graphics card for the Wii is still in development. Hopefully, everything will be finalized before the Tokyo Game Show arives...