Mistwalker is apparently developing a sequel to the Xbox360 exclusive which hasn't even reached European shelves yet, though it will tomorrow. Microsoft is reportedly happy enough with its success in the Far East that they eagerly await further additions to the franchise.
Hironobu Sakaguchi, creator of Final Fantasy, was behind the making of Lost Odyssey which is the Xbox360's second exclusive RPG from the gaming legend, the first being Blue Dragon.
While Mistwalker hasn't signed any console exclusivity agreement they're currently working very closely with Microsoft Game Studios, who helped Sakaguchi found the studio with financial backing. It seems the corporate giant has taken notice of just how viral a JRPG can be and are looking for their own taste of the magic.