it's slowly taking over for vita as the ps platform of choice. of course it will eventually become the only ps platform of choice unless sony does a reverse ps tv and literally makes a portable ps4 with games download-only.
there's a sizable amount of companies out there that are sticking with the dedicated market in japan, too. if they're not already on 3ds or supporting nintendo in some fashion as well as sony, their options are quickly going to become ps4/nx, mobile, or do ps4-only and cut budgets or do ps4-only and hope a us publisher picks it up and gets the game ported to steam.