Well, I think RE6 is Satterfield's mystery game.
Why? He said he would get it for Wii U, probably, is the only one defending the game at invisible walls and RE6 is the only big third party game left that has a shot at a Wii U version, releasing close to launch.
No way Bethesda will make a Wii U game and GTA is still far from release. He also wouldn't tease a COD game that much, when it's pretty much confirmed for Wii U