While it still is not fully supported on the Playstation 3, a recent update for Playstation 3 firmware has quietly enabled wireless support for the DualShock 4 controller on the Playstation 3.
As you probably already know, the DualShock 4 controller has always worked with the Playstation 3 but only through a wired connection, which was pretty bad considering that the cable is pretty short.
The latest firmware update for Playstation 3, as spotted by Reddit users, has quietly enabled wireless pairing for DualShock 4 controllers but the Playstation 3 sees the controller as a generic controller which means that it will not work in every game.
Also there is a problem with motion and vibration support but, hopefully, Sony will fix those soon as well.
Source:
Engadget.com.