I find it bizarre how little Smaug is in the trailer. It's basically spoiling non-book readers that he isn't much of a part of this movie. Considering they made him the unseen menace in the first movie and the Big Bad in the 2nd, where the heck is he in the third? If they could have had some more clips of him, at least people would think he was siding with Sauron, as Gandalf feared.
My only hope for this movie, which I won't see until it's on HBO 9 months from now, is that they stay true to Bilbo not taking part in the final battle. Of course that gives him jacksquat to do in the movie, other than try to use the Arkenstone as barter to stop the battle from happening, then sit around doing nothing during the fight until Thorin kicks it, but hey, I'm sure PJ has thought up a bunch of BS for him to run around doing in the meantime.
I really wonder wtf they're going to do in Dol Guldur, the little clip of Saruman makes me think maybe he'll go off alone to "finish off Sauron" but instead have a nice little chat with him and come back and say "Yep, I killed him, nope his body ... uh, disintegrated. No need to worry about it!"