i think it can hit 16m with relative ease by the end of the year. that would be essentially doubling yearly sales from where they are now, but they're gonna glide right from monster hunter into pokemon and then have the holiday period for those two to shine alongside other stuff like mario party and zelda (although zelda won't be that big of a deal).
2014 might have the 2ds, although by design, it doesn't seem well-suited for the japanese market, so we'll see. 2014 will also have smash bros dqm2, and some other stuff here and there, but it'll be the beginning of the winding down period for sure. maybe 4m for the calendar year 2014, 2/3 of what 2013 did, and bringing total sales to 20m.
then 2015 there will be another batch of titles. not sure what they could be: maybe dqxi, monster hunter 4g, radruby/sadsapphire, another fire emblem, a kirby game, or a rhythm tengoku (the latter two are very popular and currently absent form the system). it'll keep sales afloat somewhat for the year.
2016 should be another big year, but i'm expecting it more for the console side. they might do pokemon gen 7 at this time. late 2016 and/or early 2017 should see the next nintendo handheld, and leave the 3ds with about 24-25m in japan before all is said and done. not as good as the ds (which nothing may ever be again), or the gb/c (which took over a decade to get those numbers), but pretty good for its time.
