There was Mel Blanc, of course, perhaps the most famous voice-over artist of all time, the man who brought Daffy Duck, Bugs Bunny, Porky Pig and Mr. Spacely (of Spacely Sprockets) to audible life. And there was June Foray, the Hanna-Barbera/Looney Tunes stalwart and voice of Rocky the Flying Squirrel. But they were the exceptions. Even as late as 1991 with Disney's "Beauty and the Beast" — which remains one of the masterpieces of Disney's so-called second golden age — the studio used a virtually unknown vocal cast, with the exceptions of Jerry Orbach and Angela Lansbury (who certainly weren't cast to reel in the youth market). Once Williams brought real-life star power to cartoons, however, the putty tat was out of the bag.

"I can't help thinking 'Don't they already have enough money?' " laughs Veronica Taylor, a voice well-known to fans of "Pokemon" and lots of other Saturday morning cartoon shows. Taylor is a trained actress — BA, MFA, Shakespeare, summer tours — who says she "sort of fell into vocal acting" when she had her daughter nine years ago. It was all about the flextime. But that doesn't mean there isn't a certain amount of resentment toward what she calls the "celebrities only — others need not apply" policy now surrounding Hollywood animation. (Spokespeople for Paramount and DreamWorks, which together brought you "Kung Fu Panda," had no comment — likewise Disney.)

It's easy to see why actors want to voice animated characters, says actor Keith David. "The quality of animation has risen to the point where ... a lot of these features are like any movie, except you're doing it with your voice. The question is why they don't use more people who are equally as capable. There are people in the voice-over community who act as well as any star."

David, who has appeared in dozens of films and TV shows (including "Crash," "Superhero Movie" and "ER"), also has been the voice of video games, U.S. Navy ads and the Ken Burns documentaries "Jazz" and "Unforgivable Blackness: The Rise and Fall of Jack Johnson." And he knows the answer to his question.

"From a marketing standpoint, you can understand why they want P. Diddy," he says. "After you see the acting, you can wonder about the choice. Ultimately the whole policy is a bad idea, but you certainly can't fault them from a marketing point of view."