Personally, I think it's a big problem when you start incorporating the characters/movies too much into the rides. There has to be some 'perfect mix'.
On the one hand, you want to be able to experience these characters in person that you've only seen on your screen. On the other hand, rides based on transient characters are also rides which have (at least partially) transient appeal.
Take, for example, Honey I Shrunk the Audience. Many kids who are the ages of mine (8,6,4) don't have a clue about the 'back-story'. It may still be a decent show, but some of the punch is gone AND it shows its age just by its theming/content.
Now, take something like Space Mountain, Astro Orbiter, Big Thunder, Timekeeper, etc.. These can be the oldest attractions, but their theming doesn't give them away as such (maybe RETRO, but not 'outdated').
Of course, there are some characters who transcend transience into ... well... uh... 'classicity'... Peter Pan, Dumbo, Mickey, Donald, Pooh--and I'd add Buzz and Woody. Rides based on these characters are not going to seem like they are 'stale' the same way that a ride based on less popular, less enduring characters might. This is where I think I have a problem with bringing in so many Pixar characters (and I was a Pixar shareholder very much against the buyout): most of Pixar's characters have not even existed long enough to KNOW if they can break through the transcience to become true classics. It seems like they are still young enough to pass into obscurity in a year or two, leaving the rides that much less relevant.
In contrast, you've got EE, which--because it's NOT tied to any character-of-the-day--can stand for a decade and not lose its sense of timelessness...
oh, well, that's my 2 cents (I have about a dime, but I think I'd be rambling...)
