Sigourney Weaver's Ellen Ripley character will not be in Ridley Scott's Prometheus, but that does not mean she did not have something to do with the film. According to The Independent (via Blastr), Weaver claims that Prometheus was her idea!
Fox and I disagreed on how the franchise should continue. But I'm glad it's Ridley doing it, and I'll be as curious as anyone, or maybe more curious, to see it. I think he took my suggestion. Fox wanted to go to Earth, and I said: 'That's so boring. Who wants to see aliens on earth?' I said, 'Go back to the planet'.