Christopher Lee can't like this - his character dies within 10 minutes of the opening crawl of Episode III. No word on who's hand he falls by but he isn't needed long for filming since he doesn't play a significant role. In fact, the veteran actor is already finished filming with the exception of some pickup shots later next year though his new digital double is certain to be getting a workout.
So Darth Tyranus/Count Dooku is getting rubbed off early - leaving a spot empty for another Sith. Anyone seen Anakin?