This is a bit off topic, but did anyone else think Bill Paxton looked a bit like Hitler in those pics? Very curious choice of hair cut and moustache.
Anyways, being a basic shooter with Aliens in it is OK by me, my main concern is story and tension. They better not introduce the Weyland soldiers too early as I think that could really throw off the tension of the game. Take AvP Marine campaign for example. Opening absolutely brilliantly, claustrophobic atmosphere, dark, scary. Then it goes into well lit open spaces, and then you start having gun fights with Droids.
Another worry I have is they are going to try too hard to shock us with some twist in the story because they think they are making canon. Of course it could be something cool, but I think there is more a risk of it being something a bit silly. (Hicks being back is one of these things.) It's not a clever twist if some has been killed off, and they bring them back.
Multi-player I have to admit hasn't done much for me of what I have seen. The maps need to be smaller, more enclosed. Fighting Aliens in big open spaces with a group of Marines doesn't seem that thrilling, compared to walking down a dark corridor with a buddy, you turn around and he's been picked off.
Don't get me wrong, I still look forward to the game, but mostly for co-op campaign, and even then I have my reservations. I will be really disappointed if this gets screwed up because it was such a simple idea that would have worked so well.