Final Fantasy XV director Hajime Tabata said at least a couple of times last year that he'd be interested in bringing the game to the PC, but only as a "more technically developed" version—something he estimated would take more than a year to do properly. There's been no word since then on whether or not it will actually happen, but in a recent interview with Weekly Famitsu (via Gematsu) he said yet again that he'd like to see it happen, and shared a few ideas about what he has in mind.
"I’d like to release the game on PC as a technical attempt. I want to show PC users Final Fantasy XV running on high-end machines, and we personally would like to see it, too," he said. "Also, I would like to try developing on PC to pursue a unique way of playing with PC-exclusive features like making your own quests and enjoying the world using things like mods."
Tabata said that "development is progressing" on Final Fantasy XV's virtual reality content, "but we haven’t progressed to the point where we can say specifically when it will be released." He also said that he really wants to enable players to "freely travel that world by car. However, since realizing this in its existing state means overcoming some very high hurdles and tremendous debugging, the prospect of implementing it is impractical.” Perhaps in the PC version, then?
Maybe it's my natural optimism coming through, but that sounds to me just a little bit like a tease for something that's already happening. Square Enix hasn't given any indication that's the case, but I've dropped them a line just on the off chance that someone would like to.