they won't just be new games, they are new TYPES of games and with them not wanting the competition to copy them I bet it has something to do with either the gamepad or a brand new peripheral.Multiplayer meetings in single player type games hasn't been done. Think about what they showed for Destiny at E3, with drop in co-op online (at least that's what I got from it) now imagine something similar but offline where players can start playing different characters at the same time in the same or completely different area's.
We have been limited to one screen for ages and the Wii U gamepad is the first console/handheld something like this has been possible for. Would bring something different to couch multiplayer.