This is actually hard due to the release schedule :P
I think a number of these will reach 1mil, but the question is really how fast? I think Zelda will sprint to 1mil really quick so it's a question of how much of a head start these others can get and/or just outright get there before the Zelda launch. Mario Maker, Splatoon, and Xenoblade I think will all head for 1mil pretty fast, but we don't know when MM and Xenoblade are launching so it's tough to say which of those 3 has the best chance.
edit: and oh yeah, Hyrule Warriors. It's still plugging along...this is tough.







