badgenome is right by saying that MistWalker likely has multiple games in development. On their website blog, Sakaguchi has hinted that he and his team had began working on a project somewhat recently, in addition to the game that they're ready to show off this year.
Frankly, I don't care what system the games end up on. I hope Microsoft doesn't abandon them after the contract is over though. I would love for them to branch out to different consoles, as well as working on the next BD and LO for Microsoft.