Judging by the visual look of this film, I've come to the following conclusion:

given that the technology we're seeing in the trailers is more advanced than what we see in the original Alien film, I think Prometheus must take place at a time after the current Alien movies. This, coupled with the fact that the derelict vessel is still intact, would further indicate that this film will involve some element of time travel, wherein the derelict vessel, which is actually from the future, somehow manages to crash in the past...

that, or Sir Ridley Scott has completely lost his mind and is about to make a terrible movie.

Seriously, what's with the floating CGI computer screens in every science fiction movie made in the last 15 years? Where's the low-tech CRT monitors, switches and dials? I really hope Scott doesn't drop the ball on this film. We've all seen what can happen when a formerly well-respected director revisits a movie universe after an extended leave of absence.

I hope I don't leave the theatre thinking that Scott should have left well enough alone.