Didn't they try this with white knight chronicles?
Edit: beaten by the above. Souls games aside, jrpgs are a shrinking genre and an absolute Money sink. Sony throwing cash down the toilet to chase an increasingly irrelevant Japan with them is nonsensical.
I don't think the problem with JRPGs is that they're a shrinking genre per se. I think the main issue with JRPGs is that they basically became synonymous with Square Enix, and when Square Enix started to implode there wasn't anyone left to pick up the slack.
Final Fantasy was a success in the west because it was Japanese enough to be exotic without being Japanese enough to be alienating. The high production values, the distinctive art style (that isn't recognizably Japanese), the particular blend of scifi and fantasy, and the relatively sophisticated storylines (I said relatively) played really well in the West. And they'd still be playing really well in the West, I think, if Square Enix's incompetence hadn't killed the golden goose.
Final Fantasy and Kingdom Hearts sold really, really well in the sixth generation, both in Japan and in the West. Square Enix bungled the transition to the seventh generation, but the people who bought Final Fantasy and Kingdom Hearts on the PS2 didn't just disappear, as evidenced by the fact that Final Fantasy XIII sold really well: there's a lot of pent-up demand for quality JRPGs worldwide. The problem is that no one is providing them: Square Enix can't get its act together and all the other players in the JRPG field release extremely anime stuff that western gamers wouldn't be caught dead playing.
Basically, I think if someone came along and funded a game like Xenoblade on PlayStation and Xbox it would sell pretty damn well. And I think Sony is the company best positioned to do this: they understand both the Japanese and the Western market, and they'd be able to walk the fine line of appealing to both without alienating either that Final Fantasy was able to do for so many years.