I voted yes, since I think there is still a market for dedicated handheld games systems.
The lack of Vita sales have been because of a lack of western focused games and generally not delivering on the promise of Vita being the handheld to match 7th gen consoles on the move.
Sony needs to pursue 3rd party developers like they have done with PS4, they have those developers onside with PS4, so they could capitalize on that success with a new handheld.
The issues of memory costing so much have also been a major limiting factor to sales, if they'd just gone with SD Cards like the DS, 3DS and so on then sales would have been much better, people don't want to spend more money than they have to to game.
Or maybe they could just have an internal HDD, like an IPod and also have direct saves on game cards, leaving plenty of space on the HDD for games bought from PSN.
IMO I don't think the current vita situation proves Sony won't try again in the handheld market, what matters more is whether there is a market there and just because they haven't had decent success with it like they did with PSP that doesn't mean they can't with their next model.
If they do announce a new handheld Playstation I don't think it will happen for a few years, by which point the state of the handheld games console market will be much clearer.
