The 3DS Kingdom Hearts game has an official name: Kingdom Hearts 3D: Dream Drop Distance.
That's three Ds.
Confirmation comes from a Square Enix Tokyo press conference that is ongoing.
Last year Nomura revealed Kingdom Hearts 3D will connect to the yet-to-be revealed Kingdom Hearts III both in terms of gameplay systems and story. It's possible the ending of Kingdom Hearts 3D will lead into the story of KHIII.
In 3D you'll be able to control Sora and Riku, and they'll both work differently. The game's central gameplay systems are "all complete", but Square Enix is still working out how to put them into the game. The world selection for the game's Disney areas is also being worked on. SE plans to use all new Disney worlds this time around, but Traverse Town and other originals will reappear.
Square Enix has launched a Japanese Kingdom Hearts 3D: Dream Drop Distance website.