Square Enix announced today that Kingdom Hearts 3D [Dream Drop Distance], the upcoming 3DS entry in the series, will be released in US and Europe in 2012. Dream Drop Distance was announced along with the 3DS at E3 2010, but very little information has been released about the game in recent months.
In Kingdom Hearts 3D, King Mickey and Yen Sid send Sora and Riku to train to become Keyblade Masters in "The Sleeping Worlds," which I'm assuming are people's dreams. Those dreams will, as always, be set in various Disney-themed environments, including the La Cité des Cloches, the setting of The Hunchback of Notre Dame. Players will control both Sora and Riku, along with a large set of other allies.
For fans concerned about the future of the series, Kingdom Hearts 3D [Dream Drop Distance] will serve as the "opening chapter of the final conflict" of the "current" Kingdom Hearts saga, according to series creator Tetsuya Nomura...
For the record, that's the most we've ever heard from anybody about Kingdom Hearts III.