Well the thing is, SquareEnix would have to do a PS1 on us. Just take the risk and go for it, support the new console and see how it goes. Worked wonders for PS1, which really took off after the announcement that FF7 would be a PS1 exclusive. Before that, the Saturn was still doing quite well in fact. Square took the plunge and POOF they drove Sony sales up by a mile - while selling millions of copies of FF games.
So, all this "proving themselves" sounds much like a big PR stunt. They have made their decision, and whatever it is, they're just trying to keep people on their toes, waiting, driving expectations up and therefore demand, so when they do come out with a real announcement and a game, LOTS of people will know about it because it will be either the game MS "couldn't get because they didn't do well enough" or "the first multiplatform FF and DQ game!!!11".
See what i mean? It's all publicity for them. They wouldn't start developing something 6 months from now. If they will develop something, they are working right now.
Or maybe i'm the only one to think so.