The Wii Zapper is a piece of plastic which turns your Wii mote and Nunchuck into a gun-like controller. This device will be used by several upcoming games like Ghost Squad, Resident Evil: The Umbrella Chronicles and Medal of Honor Heroes 2.
The bundle will be available in November for $19. Link's Crossbow Training isn't really a full game - it's expected that it will be a series of minigames to show off the purpose of the Wii Zapper. The game will use the 3rd person perspective and will allow gamers to shoot at targets with Link's crossbow.