Square Enix, a huge supporter of the DS platform, has expressed great interest in the Wii Balance Board and the possibilities for balance control being used it "future RPG titles".
Discussing the use of Nintendo's hardware in Square's games, FFXII: Revenant Wings producer Eisuke Yokoyama told IGN: "There are no actual plans to take Final Fantasy into the fitness genre. But that whole system and mechanism of using your weight and balance to control games is something we're interested in incorporating into future RPG titles," he said.
It'll be interesting to see how a Balance Board-controlled Final Fantasy game would work.