I've got several thoughts on this...
That's a pretty major *spoiler* at this stage Ridley,,,and it would have been awesome to only find that info. out in one of the eventual trailers, or even the movie itself!
And I guess if I hadn't read it here, that I would have been unable to avoid the fact due to other sites picking up on this too.
Considering Ridley's past 'uncertainty' about how 'scary' his original 'alien' still is, I wonder if the version(s?) seen in his follow-up will be radically re-designed from his original 'human-birthed' version or not? Personally, I hope it isn't overly re-designed from H R Giger's original if any humans are 'impregnated' - but who's to say that the eggs (and 'face-huggers') won't look different to begin with in this movie anyway...
It's nice to know that the original 'alien' creatures are finally going to be seen in these 'prequels', as 'the deacon' was a disappointing design to end on previously. Especially since they are in the hands of Ridley once more - I've no doubt that he's capable of bringing out the creepiness of them again.
I guess this means that Ridley's earlier intention to lead the imagery of the sequels away from his original somewhat, has finally been nixed...and we are indeed headed back into more familiar-looking territory. Although I'm pleased about seeing these designs again, I'm not entirely sure that I want it confirmed that the 'alien' is a created 'bio-weapon' after all. Considering Ridley messed-up the mystery of the spacejockey's remains with a dissappointing 'spacesuit' solution, I just hope he handles the 'origins' of the 'alien' a bit better.
Finally, I guess this means that the 'PROMETHEUS' movie ends up a vital part of my 'ALIEN' canon now, assuming that I really like the follow-up. Makes all the time I spent on working out how to re-edit it for myself worthwhile.