I would like the option of being able to play as Aliens in ACM, but if even if that isn't going to be available, and it turns out to truly be Marine vs Merc/Weyland or other humans there should be aliens in the environment that will attack and kill plays that would add some atmosphere and build on gameplay in my opinion.
I agree with Marinho, I would like to play ACM as soon as possible, though personally its more towards experiencing the story since its suppose to be a quasi-movie type game. I still feel the servers will be busy, dont worry too much PredXeno buddy, even if for the first few months the avp servers population diminishes as ppl start playing Acm I feel that after ppl completing acm, and depending on how varied and besides the game modes and multiplayer options are, they should probably be lots of ppl coming back to play Avp if not just casually. Love it or hate it, its a unique game, and ppl seem to keep playing it regardless of whatever flaws there may be.