I'm not sure why every time I read something like this, they complain about the story. First off, KHI was made before Nomura was given the go ahead to make it a series. So that has caused some problems. Secondly, I think people complain because it's taken so long. If Versus had never existed and this saga had been wrapped up a few years ago, I don't think we'd be seeing so many complaints.
I can understand the reasoning behind the first one, if we ever gt HD re-releases I hope they insert some scenes/playable segments/ voice-overs or something. A lot could be cleared up that way if, the so far unconfirmed, BBS V2 doesn't do it first. As for it taking to long, frankly, they need to get over it. No one complained about Harry Potter taking ten years to wrap up (basically) or the gap between Twilight Princess and Skyward Sword. At least Nomura and co. have been able/nice enough to doll the story out in bits instead of making large numbered titles. What if we were still two years out from 3D because they had decided to incorporate it into III and then turn the second half of III into IV? That sounds terrible to me. I happy with what we've had and will have.
As for new worlds we still haven't been to Camelot, Dumbo's Circus, Bambi's Forest, Lady and the Tramp's city, 101 Dalmatians' London, the town part of the DI, Chicken Little's world (not sure I'd want to go there though) and Hawaii.
And they've never touched on some good films like Make Mine Music, Fun and Fancy Free, Ichabod and Mister Toad, The Jungle Book (that one's a biggie), Robbin Hood, The Rescuers (and it even has a sequel, two visits!), Bolt, The Princess and the Frog (another biggie), Tangled (and another). There's also two Mickey movies in the works. One revolving around the Magic Kingdom and another supposedly staring Mickey, Donald and Goofy called " The King of Elves". And they are also working on an adaptation of "The Snow Queen" by Hans Christian Andersen. I could see them working those in since they could be out or near it by the time we see III.
Basically, they've got plenty of Disney worlds to go to before we see Pixar worlds. Not that I don't want to see Toy Story Wall-E or The Incredibles, there's just other places I'd like to see considered first.