Mobile gaming is a factor in Japan, arguably longer than it has been in the West. Didn't stop 3DS from achieving the single best month for a console ever in Japan this December.
Even so, Super Mario 3D Land sold in excess of half a million in the USA in November. Pokemon is selling in the multi-millions despite having launched 9 months ago; selling more, in fact, than the titles sold in the heyday of the DS in 2006. We don't know how Mario Kart 7 and Super Mario 3D Land did in December, but Nintendo is traditionally very strong in the run up to Christmas.
In terms of pure profit, when single sets of games are outstripping the profit margins of the entire App Store service, it doesn't particularly point to your imminent glorious smartphone future.