The Wii Zapper is a piece of plastic that holds the Wii's Wiimote and nunchuk together like a gun, for shooting games. $20 bucks. There's a wheel coming for Mario Kart, too.
-- Mario Kart(R) Wii (name not final): Nintendo's classic racing franchise goes online. It launches with the Wii Wheel(TM) (name not final), a steering wheel housing for the Wii Remote that lets veterans and newcomers compete together. Launches globally in early 2008.
-- Wii Zapper(TM) (name not final): This unit houses both a Wii Remote and a Nunchuk(TM) and comes packaged with Nintendo software to show off its applications. Third-party developers have multiple games in the pipeline that will use this dynamic new interface. Launches 2007.