Rebellion is working on an Aliens vs. Predator shooter, and it sounds like it could be pretty cool and VERY violent.  From Kotaku:

The game is also being pitched squarely at an adult audience. A report describes the Predator’s signature move being one where he picks up a marine, snaps his neck, then tears his head off, which is followed by his spinal column. Once off, the head will continue to blink and gasp, and…well, yes, you get the idea.Pretty awesome, huh?  You can read the rest of the article, which briefly describes gameplay as a Predator and an alien, by clicking HERE.