Rob Paulsen, voice actor, has a podcast where he talks to and about other voice actors. In the latest episode, they were talking about their talented friends, and Corey Burton came up, the guy who does the voice of Dooku for The Clone Wars. They said how the first few episodes were ready and Lucas wanted to put them in the theater, so they brought in Christopher Lee to redo Dooku's voice and he apparently after hearing Burton's dub said "What do you need me for, apparently I've been here already."

Just thought that was neat.