It'll be very fun to go back and look at all these threads in a couple years, once the film has come out and whatever will be will be. I remember the pages upon pages of speculation and arguments over Prometheus in the lead up, and we were all so sure of our positions. It'll be great to have certain things verified and other preconceptions utterly smashed once again, hopefully though, the things being smashed will be any of those feelings that make us feel apprehension towards where this project is going at this point.
I also really don't agree that a retcon is a lazy writing choice at all. It's a brave choice with a lot of risk behind it. It can be executed in a lazy fashion, absolutely, but the idea behind a retcon is in and of itself not lazy.