Worlds make a return in 358/2 Days, though the system with the worlds has been changed a bit. Appearing worlds will be one of the things said to remain, but not all of these worlds will be available to be played for fun and may only be visited at certain times, or during the missions. Not only that, but the relationships between people in the worlds will be different this time around as you go through the worlds, but many Disney characters are set to make a return. The story is also said not to progress by going to Disney worlds, but that stories will be progressing. It has also been said that Roxas will have different forms, like Sora, when he enters certain Disney Worlds.
The developers have said that, with the circumstance with Roxas, if he were to associate with too many people than it would become inconsistent with KH2 which is why they are thinking of putting in a different play dynamic into each world. They have also said that the appearing worlds will be primarily from previous games, but they will be choosing ones that are best suited for the game.
In October 2007, Nomura had an interview with Gemanga Magazine where he elaborated a bit more on the Disney worlds in 358/2 Days saying that since Roxas' personality is such that he doesn't actively attempt to contact other characters, and that's why the relation with Disney characters will be different from before.
Since Roxas is the hero this time, Sora doesn't have any interaction with any of the Disney characters. But, for example, if you were to look at Beast and Belle , they're interested in discovering what love is and the players will learn about the character's hearts. Roxas learns various things from the Disney characters and before long, he becomes doubtful of the Organization.
Nomura has said that the main concern is the sticky situation with the worlds Sora has been since it can't contradict with the story of KHII. This time the objective of the events happening in the Disney worlds is to influence Roxas, gradually producing some sort of change in him. For instance, using the example of the Beauty and the Beast world again, when Roxas sees the Beast and Belle, will he be able to recognize love?
