There's a distinct possibility that Final Fantasy XV is going to be coming to the PC, at least if the HTML of the game site is to be believed.
An astute observer from NeoGAF, KupoNut, decided to check out the underlying HTML of the official Final Fantasy XV site. You know, just for fun. And while he was doing that he noticed some distinct references to each platform that it's going to be released on.
And in that code there are lines that specifically reference Windows 10 and Steam. Does that mean that we're going to be seeing this on PC as well? There's been no actual information as to whether or not it'll make that debut, but it's always a possibility, especially with Square Enix having recently released quite a few Final Fantasy titles on Steam recently.
Other than those references, there are no actual pages that are able to be publicly viewed. But other references point towards the inclusion of an about page, a trailer and eve a FAQ page that have to do with a PC version. Hopefully an announcement is made soon. Square Enix has used a DirectX 12 enabled version of their game engine to break through the uncanny valley with the Witch Chapter 0 [cry] demo that was shown in conjunction with NVIDIA at BUILD last year. So we do know that it's a distinct possibility.