The only immediately obvious way to put malware on a Wii would be through firmware updates, Virtual Console games or new channels. I suspect the only good way would be through releasing fake firmware, because I doubt VC games or downloadable channels change Wii firmware, and the worst they could do would probably be freeze the Wii up or clear saved games or something.
31/03/2007
I'm in your profile, deleting your spams for Great Justice.