http://www.mirror.co.uk/tech/kingdom-hearts-fan-questions-answered-10832218
From the Mirror's interview with Nomura:
About when KHIII will be playable at an event:
Also says in the interview that Disney is interested in making a CG KH movie. Some juicy stuff in this interview.
From the Mirror's interview with Nomura:
Ryan: Are there going to be more secret bosses? Will Sephiroth return?
Nomura: I can't say for certain, I hope, hint hint hint. I can't say for certain. In terms of Sephiroth, do you feel like you want to battle Sephiroth again? (laughs)
Ryan: I might cry, but yes, definitely.
Nomura: Even though you fought him twice? (laughs)
Ryan: My mum managed to beat him! She plays the games and she beat him!
Nomura: She's really good!
Ryan: She is! My friends were always impressed by her Kingdom Hearts skills.
Nomura: I don't think I can beat him! (laughs). In terms of the secret boss, we can't say anything at this time, but in terms of Sephiroth specifically, my development team are worried that we've had him come back so many times so they're maybe worried it might be redundant at this point. We're still deliberating on it.
About when KHIII will be playable at an event:
Ryan: Lastly, will Kingdom Hearts III be playable at any events in the near future? When can people expect to get their hands on it?
Nomura: Perhaps when we're finally able to reveal the month and date of the release
Also says in the interview that Disney is interested in making a CG KH movie. Some juicy stuff in this interview.