JRPGs aren't niche in the way some have described. Most early adopters of Sony consoles have planned for JRPG support. Especially with the PS2 where the anticipated games of early adopters was FFX and MGS2. As a genre, I wouldn't be surprised if JRPGs and SRPGs combined outsold platformers, wrpgs, or shooters. There is a distinct difference of taste in early adopting core audiences, bandwagon jumpers, and late 3rd party support based casual adopters.
Claiming JRPGs don't matter is some sort of weird new anti-360 fanboy rhetoric. You should ask the Sony core what they think of JRPGs, and Japanese support in general. See what they tell ya.
See if they'd turn down a FFVII remake or Disgaea 3, for Killzone 2. (For my money, I have a feeling that most would rather have Tales of Vespiria than Killzone 2 in the end, but we'll have to wait and see on that one.)
Saying JRPGs are niche AND that they don't matter is single minded, cherrypicking, ignorant, propoganda.
I mean, JRPG's must be niche right. I mean nobody I know has a passionate opinion about the FF series, or has ever heard of games like Chrono Trigger, Kingdom Hearts, Disgaea, Earthbound, Fire Emblem, or Secret of Mana. Those people, who know of such things, must be in some dark corner of the internet discussing them with the other guy who knows of such things.