One question though. And I'm about to get full on nerd with this because I've read a few Alien Vs. Predator novels, played the video games, watched the movies, and read the comic books.
How could Predators be hunting Aliens for thousands of years if they were created in the future?
I know that this is Ridley Scott's own interpretation of events, but he, Jon Spaihts, and Damon Lindelof just crapped on about 25+ years of Aliens and Predator writing.