In a recent interview, Tetsuya Nomura let slip a few details about the next game in the Kingdom Hearts series. While details about this new project are few and should be viewed skeptically, Nomura did state that it is not Kingdom Hearts III. It is, instead, a side-story to Sora’s tale.Part of the focus of this new story, Nomura stated, will be the events that led to Mickey possessing a keyblade, and what took place in the World of Darkness. Nomura also wants to focus on developing the character of Roxas.

Concerning platform, Nomura mentioned the PlayStation Portable, the Nintendo DS, and cell phones. He also pointed out that the official announcement had not yet occurred, but that it might come in the near future.

Even if is reporting this as true. I am going to post this as a rumor.

Source: rpgamer