To me, it doesn't look like Final Fantasy themed, plus the music sounds like from a 16-bit game, other than that, I have no clue what it could be. We're going have to wait five days for that information to be revealed.
I am surprised people didn't pick this sooner, it is the same art used for the Advance and DS Final Fantasy games it is quite obvious and the music is very Final Fantasy like so i can only assume that it is a New DS FF game.