The bolded is approximately 0% true when you acknowledge the existence of a little console called the Xbox 360.
And if you're a serious Japanese RPG fan I don't even know why you're bothering with home consoles this generation. Portables are the only real option. The DS has several more of them than the PSP, but the PSP has some good ones as well (Jeanne D'Arc, Crisis Core).
Er... the Xbox 360 so far has only had mainstream JRPGS and Eternal Sonata. A lot of JRPG fans aren't looking for the next Final Fantasy, because Final Fantasy has sucked for a while now, and Mistwalker's efforts on the 360 are distinct copies of FF games.
It's also missing what's arguably the single most hardcore RPG franchise: Dragon Quest, which prides itself on unforgiving difficulty. The DS has quite a lot of this franchise (DQIV, DQV, DQVI, DQ:M, DQIX). More importantly it's missing the diversity given out by RPGs that aren't trying to be mainstream (TWEWY, FFCC, Rune Factory), strategy RPGs (Jeanne D'Arc, FFT:A2, FFT:WotL, FFXII:RW), Nintendo's great RPGs (Fire Emblem, Mario & Luigi, Pokemon), and extensive mainstream RPGs (KH:BBS, KH358/2, FFIII, FFIV, CC:FFVII).
The 360's JRPG library is miniscule and insigniffanct compared to the handheld JRPG library. If you really like JRPGs, the 360 isn't even an option compared to the DS and PSP (Particularly the DS).