HEXiT :
although its a welcome addition it doesnt really matter. games for windows live deliberately scuppers any controller that isnt a 360 pad by reversing the sticks and in some games wont allow you to reverse them back... ala mirrors edge and wheelman.
i preferred the dual shock design over the 360 pad when i came back to pc gaming in 2007 but have since adapted to mouse and keyboard for most games. so while its a pleasant surprise that it now exists its mostly irrelevant if you already have a 360 pad or something like the logitech dual action... (still have my LDA and its still purfect even though its 7 years old)
It's not GFWL or Microsoft. What it is, is D and X input. X input is basically the 360 controllers method of input to the system. D input is another method that is used which is what I believe the PS3 controller uses which is why games that support only X input require third party software to work with a PS3 or some older controllers.
Since most games start on the consoles, and all but a few are on the 360, they normally use X input on the PC since its an easy transition and means any 360 or X input compatible controller (i.e. the Logitech F310 or F710) will work with them.
As well those same controllers will work with games designed around the D input scheme, which is normally much older games.
Add to this that drivers for the 360 are already built into Windows and its even easier.
So unless the PS4 controller supports both, I don't see how it will beat other offerings that do. Same with VALVe new controller, although since it says it will support a lot of games on launch I bet it will support D/X input.
Ryan Klug, you have to remember that it, like most every other wireless device (and some not so wireless like microwaves) use the 2.4GHz band. That means tons of interference. Honestly I wouldn't mind a RF based F710 or BT or maybe even one that pushes into the 5GHz band instead for less interference as my S4 has wireless AC and gets better signal than my Droid Razr Maxx on the 2.4GHz band from the same distance.