I've been thinking about this a lot lately. Is there a reason that a movie like The Grinch this year needs Benedict to voice their character, when he's completely changing his voice anyway and he's going to cost a LOT more and probably take a lot more training than a professional voice actor? It seems to me that you have two choices. Have the voice actor completely change his voice for the role to the point where nobody even knows it's them to begin with, or have them do a version of their own voice and have it be a distraction the entire time to people that are very familiar with the actors voice. Do these studios just want to rub elbows with the super famous? Why do they cost themselves significantly more money for something people watching the movie probably do not care about at all? People aren't going to see X or Y animated movie solely because of who they saw was in the voice cast, are they? There are starving voice actors out there that I'm sure would die for these opportunities, and probably bring something more interesting to the table.