Ive been thinking about this also. I like the idea of aliens using different senses to see in the dark, and the old one needs some obvious upgrades. Lets not focus on too many senses though, we dont need something that gives aliens an obvious advantage over marines. I mentioned this also on another discussion.
Simply having aliens and marines glow doesnt really make sense to me. But I also dont want to drift too far away from it. Alien night vision still needs to be different from marine night vision/flashlight/whatever they decide to use.
Theres got to be a way to make it look more realistic. Just a suggestion. Maybe in the dark you could have all the models outlines in white or something, nothing to much, and have lines pulsing from them in the direction that they are moving, kind of like sonar vision or something, if you get what im trying to say. I always wondered how bats see in the dark, and incorperating that into the game may give it a bit of an original edge. We could have the borders of things that arent moving ligned in white, or we dont have to. Aliens originally couldnt see things that werent moving to begin with, but this could pose issues also. Being in a dark room alone for example. Maybe things that arent moving could be ligned in white only with the alien itself is moving, the sound of its own movement echoing off the walls so it can see where its going. This would however pose a problem when it came to upgrading to silence, but it would be interesting, and original.
Perhaps it could be something that may attact people to the game just so they can see how its done, and while seeing, realize "Hey, this is a pretty cool game!"
lol
Just a suggestion, it would probably take a lot of work to pull off, i dont know. It would be cool though.