Alien vs Predator 3 is in the rumoured phase. We’ve heard nothing about another sequel since AvP Requiem was released. Producer John Davis mentioned in September 2008 that they’ve logically done all they can do with the AvP franchise.
Colin and Greg Strause were adamant that they wanted to make Aliens vs Predator 3 when they were making AvP Requiem. They essentially wanted to make an AvP film in space, in the future but by the time they were hired, Fox had already decided to go with Salerno’s script set on Earth. They incorporated elements of their ideas into the second film such as the Predator planet. ADI duo Tom Woodruff and Alec Gillis are also contenders for the director’s chair. Having worked on the alien special effects in each movie since Aliens, Tom Woodruff revealed in April 2008 that he and Alec Gillis had aspirations to direct AvP Requiem themselves.
Nobody specific has been mentioned. It’s doubtful anybody who appeared in the first two AvP films would appear in a third.
The storyline for AvP3 is anybody’s guess. From the beginning, fans have wanted an Alien vs Predator film to take place in space far in the future. The Strauses had a few of their own ideas for a potential storyline. One of the ideas took place after Aliens and another one involved the space jockey creature seen in the original Alien. Of course, a movie set in space is costly and it’s obvious the studio doesn’t want to take the risk. If AvP3 does ever get the greenlight we could end up with another poor Earth-based setting. Shane Salerno also pitched a story to Fox where the Predator ship crashed in Afghanistan and the movie revolved around a special forces team.