The Onion AV Club has an interesting interview with Billy West, the voice actor behind Fry on the ill-fated Futurama and Stimpy on Ren and Stimpy.

One of the questions he answers is why Futurama, a great show, was canceled. Not only was it on at 7 PM -- the time-slot of death -- but it wasn't promoted by Fox, since "Fox kept trying to hide it because they couldn't have control over it. How are you going to explain to the media world, 'It's a success, obviously, because we had nothing to do with it. We didn't put our seal of death on it.'"

More important, however, is West's take on regular actors getting into the voice business. In his opinion, "celebrities" get jobs in Disney features not because they're good voice actors, but because they can be marketed along with the film:

They're already looking to see what Billy Crystal is doing. This doesn't make sense, to do what they do—spend zillions on visuals, and then have this totally fucking flat-lining voice track. You know, "Hey, I'm Will Smith, I'm a clam! I'm Will Smith, I'm a kangaroo!" All you bring to the performance is your own ego. They're just being themselves. Let's put it this way: Cameron Diaz is the highest paid voice actress in history: $20 million for Shrek. Why? Because she has a 9-foot mouth? That works somewhere else, but not on tape! [Laughs.] It's like what the hell is that all about?

Voice actors got to be where they are because they're good voice actors; likewise, Cameron Diaz is famous because she's a good (?) regular actor. No one knows who Maurice LaMarche or Frank Welker are, but everyone knows Will Smith, and film companies try to draw unwitting moviegoers to crappy films (cf. Shark Tale) with the promise of their favorite big-budget stars.