Thankfully, Square Enix plans to clear the air in the very near future. The publisher's European branch told one of its inquisitive Twitter followers that “the world will get answers soon, we promise.”
The Final Fantasy X high-def update was announced back at TGS 2011 for both the PlayStation 3 and the Vita during Sony's press conference.
Now Versus XIII on the other hand... that's a completely different matter. Square Enix Europe also commented on the status of this FFXIII spin-off, confirming on Twitter that the game is "still currently in development," but "no dates to announce at this time, but we'll keep you informed. Promise."
Square Enix is sure making an awful lot of promises. Let's hope they hold to them in the coming months.