Hard to say. I think NSMBU and Nintendo Land are guaranteed. Wii Fit U is a iffy one, the two for Wii easily beat 10 mil, but this one could suffer from the 'Nintendogs 3DS' problem. I think it'll pass 10 mil, though.
Then there's Smash Bros -- I think that'll beat 10 mil. The franchise has only been growing, and a game with Mario and Pikachu on the cover is bound to sell like hotcakes. I think the first 3D Mario for the system will sell 10 mil. The eventual Mario Kart is guaranteed 10 mil.
That's 6, so I'll place my final bet at 8. I'm expecting a couple of 'surprise' million-sellers. They could be third-party, they could be some kind of Pokémon game, they could be a Retro game, they could even be Zelda if the new game captures the Twilight Princess crowd and then some.
