I loved the trailers, both of them. However, it seems as if the biggest part of the movie has been told in the trailer. Why they are going out there, something there wants to go to Earth for a bad thing, we see what looks like the Derelict and the Pilot, we see Prometheus crashing into it as if it wants to prevent it from reaching Earth. It gives the distinct impression that this ship is indeed the Derelict from Alien, and this planet is LV426, that this ship carries Eggs.
Yeah they do seem to be showing us a lot, but this is one case where I'm actually less interested in the story itself than in how Scott executes
After all, the original Alien didn't have the most original or unique story either. It was really the incredible atmosphere and gritty sense of detail that makes that movie so memorable, and I'm hoping that's the same case here.