I can see how truly undetectable artificial humans would do nicely for storyboarding and animatics, but it will be a long time before such a capability would be more cost effective than using an actor. There are so many subtle variables involved in good acting, and just as many on the perceptive/audience end ... this isn't something that algorithms will do "better" or with the same lack of predictability as a talented human any time soon. So ultimately, the creative question is "why WOULD you want to replace humans?" If it's only to save money, that will take time. If it's to avoid human interaction ... (see mateo_sancarlos' points.) Spielberg is the first to admit to his "gee whiz" sense of wonder when it comes to high tech, but as with a lot of us, it sometimes occludes real world considerations. As with any technological innovation in the arts, advanced realism should be seen as a means to an end, not an end in itself. Defining the ends should be fun. (Heh heh ... he said "occludes" ... heh heh)