as far as i know they can connect wirelessly… No games or so for that though

both the wii and the ds have wifi cards built into them, so basically the wii sends out a wifi signal to your ds, on certain games you can connect and use your ds as a controller etc…... on games like pokemon for example, you can use your pokemon from you ds on your wii, please note that pokemon battle revolution for the wii supports only pokemon diamond/pearl for the ds.