Kingdom Hearts 3D: Dream Drop Distance is coming the the Nintendo 3DS in summer 2012, and now series lead Tetsuya Nomura confirms that plans are already in motion for whatever's coming next. He says that an announcement should be coming soon in a new interview published in Japan's Kingdom Hearts 3D Ultimania guide book (via Andriasang).
That's the sum total of what Nomura had to say about the future of the Kingdom Hearts series, but it should be enough to satisfy fans for now. While we've seen a number of handheld releases in recent years for the Square Enix series that mashes together various Disney worlds and Final Fantasy, the current console generation has been completely skipped. Kingdom Hearts 2 was released for the PlayStation 2 in 2005; there's no confirmation that Nomura's hinted-at reveal will be for Kingdom Hearts 3, but that's certainly the hope.