Yesterday, the official Final Fantasy XIII Japanese portal site was updated giving us a big surprise: the Steam logo appeared alongside with the PS3 and Xbox 360 logos. Obviously, this could just be a mistake, but it also could mean that Square-Enix is going to port the FF XIII saga to PC.
During the past gen, S-E only ported the online titles of the saga to PC , FF XI and FF XIV; the offline titles remained exclusive to consoles. In fact, since FF VIII, the company has not ported another offline entry to PC, so this would be a moderate surprise if it comes true.
At one point, the US FF XIII website also hinted a possible PC release, although the release date was never shown. The info was quickly removed from the webpage, but here you can see a screenshot: