I've played almost every JRPG released for the 360, and I've gotta say, the genre is still going strong and I still love them.
FFXIII may have sucked terribly, but Lost Odyssey, Resonance of Fate, Tales of Vesperia, Blue Dragon, Eternal Sonata (cutscenes aside), Enchanted Arms, and even parts of Star Ocean: TLH were very good (pretty much ranked from good to mediocre).
Operation Darkness and Spectral Force 3 on the SRPG side were pretty good, but were frankly too hard to be a lot of fun.
Magna Carta 2 suffered from using the same engine as Infinite Undiscovery (which I found to be a broken pile of frustration and yelling), but was still ok.
I only really became a "hardcore" gamer this generation, so the majority of my experience with JRPGs has been recent, and I'm still very pleased with the offerings. I wish Mistwalker would keep developing on the 360, but it doesn't look like they're going to... I love Sakaguchi and his crazy surfing lego man.