The Shock Factor...

Sorry if someones already covered this, but something that popped in my head today is, will Prometheus have that same shock factor as Alien? Although I didn't see Alien when it was released in 1979 (as discussed in another discussion), it is often talked about how much Alien terrified the audience. Ridley Scott recalled how in a test screening, a young couple were wrapped around each other in sheer terror. It was so unlike anything before it, so it was so effective in the scare department. So I was wondering, in the modern age would Prometheus have that same effect? Ridley has said (& I quote) he want's to "scare the living sh*t out of you", & being one of the best (if not the best) directors, I'm sure he knows what he is doing and what buttons to press. & he has promised at least one moment in the film to rival he legendary chestburster scene. But what with all the images & and promo vids floating about showing more & more of the film, the 15 rating as opposed to Alien's 18, and the fact that since Alien we've had so many films to shock us (all the "Saw"s and such like), will it terrify us as Alien did? Not that its all about the gore, indeed Alien was so terrifying because you rarely saw the monster but you knew it was there. But I wonder if we are a bit anaethnatised to it all these days. Personally I think from what I've sen theres enough in there to scare the bejeezus out of us, plus Mr Scott won't have let all the shocks & scares out of the bag at this stage. But I just thought I'd see what others thought..