Believe me - I'd much rather see Disney cast more unknowns for talent rather than name. I think it makes the movie more believable if you haven't seen or heard the person in a zillion other movies. Especially in animation. I can warm up to a character much more quickly if I see the character as the character and not the voice. Some people can pull this off, others can't. I mean, Mrs. Potts was Mrs. Potts, not Angela Lansbury - but compare that to the donkey in Shrek - I mean, that was definitely Eddie Murphy, not the donkey character.
Personally I'm getting really tired of John Goodman's voice in so many animated features. I can't believe he's doing the voice of Baloo. He was great as Pacha, but I can't see him doing Baloo at all. Doesn't sound anything like the original Baloo - you'd think Disney would try to find someone who sounded more like the original character, but no.
Anyhow... I'm ranting and off topic, so I'll quit typing now.