Yes, and they normally do more than one trailer, don't they? For example, with Eclipse they had one trailer which concentrated on the action bits of the movie and then they had another trailer which was focused towards the lovey-dovey romantic parts of it, so I am hoping they do the same for Breaking Dawn. They are just keeping us in suspense!
"You want a nice stereo? Drive your own car"" (Bella, New Moon, ch. 1)
"They’re just cliff diving, Bella. Recreation. La Push doesn’t have a mall, you know" (Jacob, New Moon, ch. 7)