In ten to twenty years most people well ask "who?" when you will read the names of these actors.
Technology is making them obsolite, most of Sky Captain was computer generated as was Polar Express and some of the biggest movies lately was animated ones such as The Incredibles or Shrek.
Why pay Cloony 20 million dollars to make a movie if the technology becomes cheap enough to create an actor without all the problems and egos of current hollywood.
The Movie Studios isn't sending out Golum from Lord of the Rings or Homer Simpson to support stupid political causes or get arrested for drug abuse and they never get old or unable to work. Lord of the Rings might be the last big real actor movie success if trends continue.
Not quite yet. Both Sky Captain and The Polar Express have not perofmed well at the box office.