I'm surprised how few people are predicting Skyrim. I acknowledge it's "old", but the game is a perfect pairing for Zelda and has not appeared on a Nintendo console until now. I bet Bethesda(?) is very excited to see how Zelda is flying off the shelves.
ARMS I am not as optimistic about as a lot of people in this thread, but admittedly Nintendo does regularly pull 1 mil with it's game.
I think around 5-6.