The leaked one? I want a full 1080p HD trailer lol!

He didn't say anything about Alien creature being or not being in the movie and he kept talking from a director's perspective since he obviously doesn't want to spoil anything but it is obvious that this movie is an Alien prequel and when he said it transformed into something else, I'm sure he meant that it won't be just about suspense and what one character does to survive from an alien creature but instead will have major action elements and setpieces too (as seen in the leaked trailer). Not to mention the scream in the trailer and the way Prometheus logo gets formed is obviously from the first Alien's trailer. And also you can see the derelict and Space Jockey's chair in the trailer.

he was asked about the Alien in one interview.

http://www.cinemablend.com/...

" Here's what he had to say when asked directly if we would again see the xenomorph in the film:

No. Absolutely not. They squeezed it dry. He (the xenomorph) did very well. (He laughs) He survived, he’s now in Disneyland in Orlando, and no way am I going back there. How did he end up in Disneyland? I saw him in Disneyland, Jesus Christ!"

so unless he's just throwing a curveball to keep people guessing it seems like we won't be seeing The Alien in Prometheus.

either way i can't wait to see the film, let's face it, Ridley Scott makes damn good movies.