My take!

Buck Tornado
MemberOvomorphApril 30, 2012664 Views9 RepliesI am not sure if this has been discussed but in the trailer Shaw is crawling post-abortion towards 3 guys and one is in a wheelchair. I'll bet it's Weyland in the wheelchair and since this film is about Gods and monsters I'm going to say that nobody knew that he was along for the ride. He is old and wants to be young again (or immortal) with the help of the alien technology. He gets infected, becomes strong and that is the Gigeresque figure approaching Shaw at the end of the trailer.
It's just more dramatic to be him as opposed to Holloway and I don't think it is David. I'm thinking that it's David who pilots the ship into the croissant.
And in the trailer where it is crashing to the planetoid, it is Vickers and Shaw running from it, but methinks that Shaw is also running AWAY FROM Vickers.