I can't see actors being replaced unless people go in knowing its a CGI movie. What I do see are models being replaced. Its far cheaper to render a model who can pose in any position, have any proportions, never complains, never is late, is always fit and always young as opposed to a model like Cindy Crawford or Cathy Ireland. What I find interesting is the crossing of the two mediums. Taking the nude pic for example. I real photography they try to eliminate the skin bumps, wrinkles and textures. In 3d they try and enhance them. If that were a real pic of a nude girl I doubt you'd see the skin bump pattern at all. One of the big problems is the 3d renderer does not simulate a real life camera. On a camera details are lost, not added. I think the industry on a whole needs to step back and look at the subtle things that humans use to identify reality. 3d renders are too perfect and that's what kills the illusion. Freckles, skin bump maps, sheen on skin should be extremely subtle, not super high definition. Seeing pours on faces isn't even in real movies (actresses wear make up to cover that up) so why have it in 3d movies.