It needs a change in the OS user interface. Make it like and android phone with the actual android OS+Vita Os in the system.
If people are going to buy this thing it needs to feel accessible, and not weird.
Also much better would be an Xperia V (ita), it should be a bit thick, so that when you press a physical button in the phone the part in the back slides to the sides of the screen so it would offer actual buttons, and 2 analog sticks like the ones in the PSP, so it does no take to much space. Ideally it should resemble the form of the VITA a lot. And also the user interface should be like the one in android phones, but the actual OS a combination of android an vita.