Nomura actually hasn't drawn any specific drawings for Kingdom Hearts 3D yet. He's actually looking into an idea of changing Sora and Riku's clothing. One of the reasons for this is that if the characters appear in the same clothing, some people might think that KH3D is a remake.
Of course, Sora and Riku have to appear in their original Kingdom Hearts forms as part of the story. Nomura said that he's considering having them appear in their current clothing at the start of the game, and change midway through.
