Aw man...Tell me you're not thinking about the same idea that I was thinking about? Utilizing the "global brain" to manufacture ideas and scenes for movies? Yeah, I think it can and should be done and if its ever pulled off, I think it would fundamentally revolutionize the movie industry and bring about a new renaissance to film.
The problem of course, is the nature in which films are made. They need to be controlled by a few people because the expression of that film in reflecting the real world is volatile and subject to ruin by even the simplest of things. However, I think because of that, we naturally gravitated towards a sort of "monopoly" in filmmaking and that of course, includes the creative process.
Movies are made by highly professional writers behind closed doors, but those writers only have a limited view of reality and in effect, never seem to give the most accurate and interesting depiction of the World. In fact, no one individual can do such a thing, but if there was some way that you could tap into a large online community and grab ideas and suggestions from that, you could generate an almost infinite variation of characters and plot development.
Obviously, it would have to be well-thought out if you could ever develop a way and use that for professional Hollywood movies, but I think its an amazing concept.