Valve has confirmed that it will be fully supporting the DualShock 4 in Steam, with that set to be added in a new update. Previously if you wanted to use the controller for PC gaming players  had to use third party programs to properly configure the button layout. The update will allow players to use Sony’s controller including the gyros and touchpad for various games, without having to go through extra steps.
Valve will be adding other controller support in the future, but the DS4 has been chosen for now due to how much it overlaps with the Steam controller.
Source: Gamasutra
bunimomike
Utterly, utterly wonderful news. It’s already becoming easier anyway but to have official support. Well… that’s just great. :) It’s a brilliant controller in my humble opinion.
ron_mcphatty
There you go mate, that seals the deal on the wireless dongle eh! This is wonderful news and totally unexpected, no more ABXY confusion for me.
Severn2j
Thats great news, although it does make that Xbox Elite controller I bought recently look a bit pointless..
Although, not as much as the Steam controller, which I still cant get my head into.
Stefan L
Well… the Elite controller is the nicest controller I’ve ever held in my hands, so I’m not sure I’d call it pointless.
ron_mcphatty
The Steam Controller is very pointless though! I really couldn’t get on with the touch pads and the build quality was so far behind the XBox and PS4 controller that I had to get rid.