The resemblance is very impressive.
Though, I'm certain that Pixar creates some of their characters as caricatures of famous people from Old Hollywood. For example, I thought everybody knew that the old guy from UP is (an older) Spencer Tracy?
Further, WALL_E ran with the short PRESTO, which featured a magician that looks like William Powell.
And in keeping with the old Hollywood theme Edna Mode, the super-suit designer on THE INCREDIBLES, is based the renowned Hollywood costume designer Edith Head. (some debate this, but I think the characters based on Powell & Tracy point definitively to Old Hollywood basis)
