The problem is, Nomura and Squenix can't cut out the Disney elements completely - there are just some things which have put their roots so deep into the KH world, that to tear them out would destroy everything (ooooh! I've just worked out the plot for the fourth KH game!
). Things like King Mickey, Donald and Goofy, Maleficient. Thankfully they've grown into their individual roles, and they fit. Whereas things like Atlantis *shudders*.
As the series matures (looks like it will do a lot, if the CG video is anything to go by), then methinks there'll be a lot less Disney. In KH1, Disney played a big part, and the storyline wove it's way through each world due to the six Princesses of the Heart. In KH2, however, the story seemed to be a lot stronger in the Squenix worlds. Personally, I think that the story progressed, and was a lot better, in the Squenix worlds, rather than Disney worlds. Saying that, though, one or two Disney worlds were on par with Squenix worlds (Beasts Castle, Halloween Town, Disney Castle).