HappySqurriel on 02 November 2009
The SNES, N64 and Gamecube were designed with the intention of releasing add-ons after the fact (SNES-CD, N64 Memory Expansion pack, N64-DD, GBA Player, Modem/Broadband Adapter, etc) but few were ever released worldwide; and none were particularly popular. The Wii was designed to be a much more feature complete system, and most of the functionality I would expect Nintendo to add would be through software updates or new controllers. From a technical perspective there are things that could be done through USB, but nothing which would have much of an impact on hardware performance because the bandwith of USB simply isn't high enough.
