just watched this again, and my first thought was, why the hell didn't they just film the sequel at the same time like everyone else does these days? now we may not get one at all.
other observations:
are we to believe that 3.5 billion years ago, that alien dude came to earth, drank that shit that disintegrated him, and started life here, but they only got around to wanting to kill us off 2,000 years ago with the bioweapon? i'm with naomi rapace on this, why? or more specifically, why bother?
also, how does any of this jive with the predator timeline, esp in avp and that pyrmid in antarctica? or does it?
ridley scott has said there was nothing cut out of the film [disappointment, because it could use a few things put back in], but then this still surfaced:

so... was it take-your-dad-to-work day in alien land? or was old dude just using young dude for the experiment? was young dude getting sandusky'd? i need to know.
this film is very gray, even the aliens are gray. color scale is not the most important thing in the world, but this one has as decidedly gray a grayscale as you can get, as opposed to say something like csi miami's almost cartoonishly bright coloring. it definitely lends itself to the cold [but not frozen] grimness of the film, a visual allegory to lifelessness, i guess.
the film actually doesn't answer a lot of questions from the previous alien films, although it seems the sequel might have. it is basically just the addition of the engineers characters and their agency in the saga, but it remains oblique, while looking great. it is most comparable to the first film, being more esoteric and having an amazing cast of a-list talent, and yet doesn't do a whole lot with them storywise. i fully expected a 3 hour director's cut version with tons of explanatory dialogue, but such is apparently not the case. as it stands, this ranks below alien1, and maybe below alien3, but i'll have to rewatch that one to know for sure. i still like it, but it just feels incomplete, and not in the "it was so great i wanted more" way, just incomplete.
also, i'm guessing tony scott's killing himself may have permanently shelved a sequel as i understand the brothers were very close. will probably affect ridley scott's output in general for a few years.