A new MonHun, a MAJOR exclusive from a popular Japanese franchise, a new hit property that appeals to a younger/more casual market (Animal Crossing type), and probably something from a hot cross-media property. That could make Vita sales jump.
At the same time, of course, the 3DS would have to see a serious decline. Let's say, for instance, that Nintendo pissed off Japanese publishers and that they had all their internal studios working on Wii U games.
Short answer: zero chance.