When you buy Battlefield 4 for the PS3, there is an option to upgrade your purchase to play the game on the PS4, just in case you’re also doing the same console switch as everyone else.
When you buy the game for the PS3, there is a unique voucher inside the copies, which will allow the player to download a copy of the game on the PS4 until March 28, 2014. Of course, it comes with a price, but at a lesse $9.99.
Lots of other games are doing these upgrade deals. Call of Duty: Ghosts is one example. Let us wait for the upgrade details of other games when announced.