I'm still willing to bet our world count will be 20, especially since we're eventually going to have to go back to certain worlds like Castle Oblivion/LoD, as well as other realms, like the Realm of Darkness. I don't know how many will be returning, but I think it's safe to say that any Disney film that had a sequel (Aladdin 3, Lion King 2, POTC 2/3, etc.) or was popular enough to warrant a return (Nightmare Before Christmas) will come back. We also don't know yet if the new worlds will be exclusively Disney/Pixar properties or possibly anything else Disney acquired since DDD. Either way, I don't care about the world count so long as there's a real rhyme and reason to go to worlds that ties into the overall plot, which KH1, BbS, and DDD all did fairly well, though some better than others.