There's one that doesn't make sense to be released on as an exclusive: Xbox 360. JRPGs don't generally do very well on it. Other than that, almost every other platform is possible. Wii is popular and probably can support JRPGs as well, PS3 could definitely suppport a JRPG like this, even in the west, PSP could suffice in Japan, DS is always a decent choice. That said, there are three likely possibilities in my opinion.
First, a PS3 exclusive is what most think. It would probably make sense, considering how well PS3 has done in Japan and that many JRPG fans in the west may own PS3. Then there's the chance it'll get released on both HD consoles: I already explained PS3, and 360 wouldn't hurt the game either (though not necessarily the best choice either, as I already said). Then there's also the chance it'll get released on Wii. A huge userbase which could probably be interested in JRPGs is good.
Of those three I think PS3 exclusive and Wii exclusive are the most likely. I think I'll lean slightly towards Wii exclusive; Kingdom Hearts just seems to fit pretty well for Wii. Of course PS3 isn't bad either, and I'm sure they would both be excellent choices.











