I'm actually looking forward to this and think an aliens rpg could be very fun to play if it is done right. I'm hoping that it will be a fps/rpg hybrid similar to the likes of vampire the masquarade bloodlines, system shock or deus ex.
Set it on a large colony where your character's job defines his/her's skills (eg a doctor would excel in first aid, a member of the security force would excel in using weapons). Add some party npcs that follow your character around and base the story around the fall of the colony: at the beginning of the game, things are relatively normal as you form your party and interact with other npcs in the colony but as the game progresses, the humans numbers starts diminishing, the aliens numbers starts growing, the humans start losing control of the colony and tensions within your group start to rise as the surviving humans start fighting each other because the hope of surviving through the infestation begins to diminish (think "day of the dead").
Skills based on diplomacy and conversation may be able to ease in-party arguments and allow you to negotiate and reason with other humans whereas more practical skills will help you survive encounters with aliens or create better weaponry and equipment (think back to alien when the constructed their own crude motion trackers and flame throwers).
Anyway, thats just a few ideas that I think might make an aliens rpg work.
