I think movie pitches should be made via mock-up trailers. Start releasing trailers for unmade movies online and just see what generates the most buzz. It's not a guarantee, of course, but it's a cheap way of testing the waters without having to get the whole production together, and it involves the movie-going public rather than just a few producers. It would also help to democratise movie making, even though you still need those producers and their money.
Mokalus of Borg
PS - By the time you get the real movie together, though, the world may have moved on.
PPS - But that's always a risk.