Not really, in Japan definitely but in the west it's not as concentrated as that, it's not like the last generation where jRPG fans all brought a Playstation, it's been spread out a bit, The person who got me to play jRPG doesn't own a PS3, neither do most of my friends wh grew up on JRPG's, however the truth of the matter is in Japan the 360 is dead, it never really had a chance really, as Japan unlike the west tend to look at foreign brands like a invasion and avoid them to protect their own national brands, this has in recent years backfired on them in the games industry as the rest of the world has moved on, developers don't care to break the market, and foreign consumers of Japanese games is declining, it was one of the major leaders globally but with the exception of a few multinational brand names, most games are made for the japanese market only.
What I'm trying to say is that the PS3 is more designed for RPG than the 360. 360 is more focused on shooters, race games, western RPG games. The PS3 can focus on all those categories but it also specialize in JRPG because it's Sony example the FF series, Valkyria Chronicles, Eternal Sonata and the Tales series. I really hate the reason that Vesperia on the PS3 isn't going to be release because Microsoft owning the rights damn
. Of course since the PS3 version is way better they don't want their rival company to release the game.