I don't know how it'll play out, and I'm happy because of it. Almost every other movie I've seen recently I knew how it would end. I like surprise.
I saw a movie a few months ago, a Liam Neeson movie called Unknown. I had free tickets, so I saw it. I hadn't seen any ads or reviews or synopses. I took in the story completely in the dark and liked it enough. I saw the ads later- they spoiled everything and I'm glad I didn't see them first.
That's what I like about Prometheus. I don't know the story, and I hope I continue not knowing.