F*ck. It's a rumor..

I checked, here's a story explaining it:

Weaver Denies Alien 5 Report

Sigourney Weaver, through a spokesman, denied widespread reports that she was going to be paid $22 million to reprise the role of Ellen Ripley in a fifth Alien movie, Variety columnist Michael Fleming reported. The Alien story first appeared in the British Sunday Express tabloid newspaper and was picked up by the Reuters news service. But Fleming reported that no new Alien movie is in the works, and that her quotes came from an old press junket interview. The Express had also reported that Buffy the Vampire Slayer creator Joss Whedon would pen the script; that also appears unlikely.