We know of a few:
The Conduit
EA Sports Tennis
Red Steel 2
Tiger Woods 10 (hinted at but not confirmed)
I expect Nintendo to make a big deal out of WM+ games coming out at E3
Others that you can expect: Mario Party 9, Rayman Rabbids 4, Warioware, other sport games, other party games. I question how well Nintendo will support it itself though, because as of yet their barely supported their own balance board.