It's not a spoiler to say this film is about the "Space Jockey" species, at least, is it?
Unless you've managed to ignore the media since last year?
I watched the trailer for Alien the other week. I hadn't seen it before and was vey surprised how misleading it was, in regards to the film's actual plot.
If the Prometheus trailers are similar (and I suspect so due to Ridley S.) we know bugger all. Apart from "Spaceships, aliens and stuff" as Rose Tyler once said.
The link to the article on THR does have spoilers of sorts which folk might want to avoid, as the article contains information not apparent in trailers/previous interviews/etc.