With Square Enix being giant-sized, they can afford to work on about three games at a time, at least. As for the Final fantasy games, Square have always only released three games per console; 1, 2 and 3 on the NES/Famicom; 4, 5 and 6 on the SNES/Super Famicom; 7, 8 and 9 on the PSX, and 10, 11 and 12 on the PS2, so when FF13 rolls around, I dare say it'll either be on the PS3 or whatever nextgen console they pick/get a contract with.

Oh, and wrong forum =P