Theory: I just noticed something about the DS4...

[Mystro-Sama]

vivster said:

No. The touch pad is hardly functioning as it is. You can't replace a touchscreen with a touch pad. You can't look at what you're tapping. The only thing the pad can be used for are gestures.

So the only games you could port are the ones that don't facilitate the touch screen properly in the first place and could've been done without one.

You realise theres a touchpad on the back of the Vita as well, right? lol

With that out of the way i'm sure they could map the touch controls to the thumbsticks or buttons.