Sony’s PlayStation Vita, handheld will not work as a controller for all games on the PlayStation 4. Sony Computer Entertainment president of Worldwide Studios Shuhei Yoshida said “that the PlayStation Vita will only work as a controller on the system if the game’s developer has specifically designed the game to take advantage of the device”. Unless a game is specifically programmed to allow such use of PS Vita.” So it’s up to the developers of the games to add in the code for this function. It is similar to what happened with Remote Play on the PS Vita via the PlayStation 3. This was a promised bit of added functionality to the Psvita but it requires extra coding by developers and an inevitable strain on software speed, so it failed to take off.
Reports earlier this year suggested that Remote Play would not require additional coding to make PlayStation 4 games work on the Vita. While slightly different from using the PSvita as a controller for the PS4 system, all games, except for those that take advantage of the PlayStation Eye or PlayStation Move peripherals are believed to include native support for playback on the company’s portable hardware.
So it going to be like Little Big Plant and Marvel vs. Capcom 3 with cross controller. The one good thing is you will not have to buy both games to play cross controller games.
The good news is that the PSvita can be used as a PS4 controller.but I can’t imagine it being worth it unless devs make Wii U-like games that really take advantage of the Vita’s screen. Just like Little Big Planet in the video below.