Quake3World

It is likely to be the death of Ninten...oh no it won't as they will release every single game they have ever made again as an over priced download for it

I never said it was a good idea
The only real interesting application is to have one player play a meta game on the pad (like a D&D dungeon master) while the other players are active in the same world. This is hardly revolutionary though, as it would always have been possible with online play, now you can just get that experience with friends on the same couch. That is a plus, but not something to build an entire console around. Also, the requirement of additional people participating in the game in your house is a steep one.