A theme is an story/character/idea that we can all relate to and recognize, like Snow White/Mickey/Conservation.
... I disagree with the definition of "theme" we're using, here. A character, in and of itself, is not a theme. A theme is an underlying idea or story, true, but a character is a device used to express the theme.
The Peter Pan and Snow White rides are themed in the sense that they tell a story. You do not have to have any prior knowledge of the films to "get" the story. It's A Small World is themed in the sense that it conveys the underlying idea that people are people and our differences are superficial (although you can't tell that from some of the discussion on this board). You do not need a prior knowledge of what IASW is about to "get" that message.
Dumbo is not themed, it is decorated with a recognizable character. Without a prior knowledge of the movie, there is no way to discern a meaningful story from the Dumbo ride. Yes, a lot of people _remember_ the movie's theme from seeing the Dumbo ride, but the ride itself is not themed, it relies on character recognition to recall a theme from somewhere else.
There's a pizza buffet here locally with pictures of cartoon characters on the wall. Mickey and Donald, Buzz and Woody, and so on. If characters in and of themselves are "theme," then that pizza buffet is at least as well-themed as Dumbo, and arguably _better_ themed (hey, there're more characters there, so that means more theme, eh?).
Port Orleans French Quarter/Riverside actually tells a story (arguably a better story after the name change, but that's not important right now) with it's buildings, landscapes, and of course, the Sassagoula River. The All-Stars are decorated with giant icons, not themed. Any story or idea brought to mind by those icons is a memory triggered through character recognition, not a theme expressed by the icon.
If a company makes a cheap plastic coffee mug, everyone can see it's a cheap plastic coffee mug. If that same company makes a cheap plastic coffee mug and screens on an image of Mickey, is the cheap coffee mug suddenly Magic? Or is it a cheap plastic coffee mug that _reminds_ you of something Magic?
I don't intend to get into the IOA/Disney thing at all, I just wanted to clear up the mistaken use of the term "theme." The mistaken use doesn't happen only here, I believe Disney management is now convinced that "character" equals "theme," and I believe that mistake is leading to less Magical rides.
It is my opinion that Disney's recent projects tend to use character recognition in place of real theming far too often, and that this trend will bite them in the future.
Jeff