It's slated to sell about 13.5 million this past year and that was with Pokemon X/Y, Luigi's Mansion 2, Animal Crossing (West), 2DS (West), Monster Hunter 4 (Japan), Mario & Luigi, Dragon Quest VII (Japan), etc.
Moderate estimates
2014: 12.5 million
2015: 11 million
2016: 9 million
2017: 7 million
= 82 million
Nintendo's big problem are tablets eating up the kiddie audience, that's why they can't sell DS or even peak GBA numbers anymore even with Pokemon X/Y and Monster Hunter 4.
Model revisions are fine but they don't change the fact that Nintendo's blown their wad on most of their big IP and the Monster Hunter audience is also there. To get audiences coming from elsewhere they need to create a new franchise that brings in a new audience and/or do something like money-hat a Final Fantasy VII Remake. I can't think of much else that would move tons of hardware.
