I don't see why a Pokemon game boosting sales is so unimaginable. The thing with it is, it needs to be a proper, full version of Pokemon (possibly mmo-esque, but at least Monster Hunter levels of co-op play), ideally developed by Game Freak. Not some company I had to look up on Wikipedia who apparently have done nothing of note since their ill-fated Gamecube attempts (although Colosseum really wasn't that awful).
The problem with this is: why would Nintendo want to do that? Unless it was some kind of home console crisis where they had exhausted all their other avenues *coughMarioKart* and the thing still wasn't taking off, there would just be no point. Game Freak can just use less resources to make a handheld title which would still sell more copies, thus netting more profit.
So yeah. Unlikely, but you never know.
And to answer the question, as I hinted at before, the answer is most likely Mario Kart. Or, Mario Kart + new Mario platformer + price cut. Since we've seen that one work recently!







