The trailer appears to be an extension of the previously released teaser trailer. It features some of the characters’ reactions to receiving an invitation to Edward and Bella’s wedding. This includes the Volturi, Bella’s mother and a very unhappy Jacob (that no matter what, takes off his shirt and shows his abs).
That’s not it because the main thing that happens in Twilight: Breaking Dawn Part 1 is the honeymoon and the pregnancy.
Breaking Dawn Part 1 arrives in theaters on November 18, 2011