Final Fantasy Haeresis isn’t announced yet, but it was patented back in May 1, 2006. The same month when the other Fabula Nova Crystallis games where announced. Until now there isn’t anything known about the game except the above logo which was found a long time ago. A background image wasn’t found.
It was rumored a long time that this game would be an online RPG but it turned out to be Final Fantasy XIV. Square Enix themselves didn’t say anything regarding this game, but like FFXIV it could be that this game is in development silently for 4 years and suddenly announced for release next year.
The latin word Haeresis means “heresy” which could indicate that the story is similar to the one from Final Fantasy X.