This year should rack up loads of million sellers for the 3DS! Luigi's Mansion, MH4, DQ7, Tomodachi, Pokemon X/Y, Pokemon Mystery Dungeon. There's a possibility of other games as well like Layton vs Ace, Inazuma, etc.
Also how many 10 mil sellers will there be by the end of this year? Most probably 3 (SM3D Land, Pokemon, MK7). NSMB 2 has an outside chance (maybe downloads have increased more than we think), AC won't do it though.