In his first interview since AvP, Ridley Scott made a small comment when asked if he would do Alien 5 in an interview with SciFi. As reported on JoBlo’s:
“But Scott added there’s one SF story he doesn’t want to revist: a fifth film in the Alien series. “No,” he said with finality. “I think they’ve wrung it dry.”
Looks like AvP destroyed any chance of Ridley Scott doing Alien 5.