At the moment it's not out, but it will be available for you to see very very soon.
No in the credits of kh3d kingdom hearts 3 was confirmed.
they re already doing it Kh3D (Dream Drop Distance) for the nintendo 3DS
Square Enix generally takes a 3-5 month break inbetween the releases in Japan and NA. They also have to translate everything for us. But, James Patrick Stuart recently statted on his facebook that he was leaving to start voice capture work for Xigbar/Braig for KH3D. Which means the game should be coming to us around June-July.
somewhat confirmed by the team. they haven't started on it yet because they are working on FF. but you can expect 2 games before 3. KH3d (3ds) and Kingdom hearts birth by sleep part 2 (possibly for the vita)