In a recent interview in Famitsu Tetsuya Nomura said thatKingdom Hearts III: "will be implemented as soon as possible". Which is the biggest confirmation for the third installment in Sora's main quest to date. Chances are the same team that made BBS (which is based in Osaka) will be working on KHIII. For those of you who are wondering just what this team can do (besides BBS) seen those little trailers for FFVersusXIII? There's your answer.
So... possibly the beginning of development once FFVersusXIII is out? So... three years until III? This'll most likely be the first KH game out on the PS3!