Oh boy, I hope the game will be as cool as these screens!

When playing as Predator I always wanted to grab a human before killing him to give a feeling of superiority and looks like pred players will have this ability. Look into his terrified eyes before killing him.

Alien tail-kill will not simply instantly kill a marine but swing him in the air. On the right side we see an alien sitting and chewing on a marine. Maybe a knock-down-and-kill move?

Playing as a marine was the most fun mainly due to the lack of vision and the feeling of vulnerability, especially in dark places with flickering lights when night vision wasn't much help. The motion scanner did provide a warning but in most cases aliens dropped from vents where you can't shoot them.
The first marine appears to be knocked down but still alive and shooting. (possible co-op missions like in left 4 dead?) Which isn't actually a bad idea.
The game will be released in early 2010 on all consoles including PC and Xbox. By the looks of thing a PC upgrade will be required to play :(
Still, I can't till it comes out.
One more thing for you Alien and Predator fans. Aliens vs Predator 3 (AVP3) the movie is also scheduled for 2010. Although the games were much more successful and popular than the movies we (the fans) still can't help and feel hopeful that this time tey will get it right.
Here's also a trailer for the upcoming game.
The trailer is just awful but according to the unwritten law of trailers: "the worse it is the better the game/movie."
the screens look really nice