Some images have come out of the Predator-based Alien from the upcoming Alien vs Predator 2 (or AVP2). It was established in the Alien movies that the creature takes on some characteristics of whichever creature it gestated in.
I don't really remember, but apparently one of the Aliens infected a Predator at the end of the first film.
The first AVP was a train wreck of a movie, offending fans of both of the characters. There's a whole new team behind the sequel and one can only hope that this one will be an improvement.
Head on over to JoBlo to see more pics of the creature.