I don't watch trailer. They ruin movies. Specially comedy movies. They just put the most intense parts or the best jokes of the movie in there, and you have no reason to watch the movie anymore. For example, you might see a scene near the end when character X, and in the movie, in the beginning, the same guy is about to die, but you know that he won't since you've seen him in the trailer.
The title Alien tells you that it's going to be about aliens, but although my english isn't perfect, I'm quite sure nothing in "Inception" links you to dreams. Of course, it might be the main focus of movie, but having seen Shutter Island, it would've make a lot of sence if it was part of the final plot, and like I said, I have no way of knowing that.
As said before, I didn't read anything about the movie. In fact, I barely even knew who made it. Staying far from spoilers is pain in the ass with people like you guys.
