Pokemon Mystery Dungeon has been announced for 3DS.
The title translates roughly as Pokemon Mystery Dungeon: Magnagate and the Infinite Labyrinth. The Magnagate refers to portals in the game that allow your Pokemon team to teleport into dungeons. New Magnagates can be created by scanning things using the included AR feature. The things that can be scanned have not been revealed yet though.
IGN has reported starter selections are out of Snivy, Oshawott, Tepig, Pikachu or Axew. The last Pokemon Mystery Dungeon release on DS was Explorers of Sky in 2009.