As of Thursday afternoon, over a week before the first show, 2,344 showings of Twilight: Breaking Dawn Part 1 have been sold out by the major online tickets sellers (MovieTickets.com, Fandango), according to Deadline.  Theater owners are adding shows, according to the report. 
Merchandising opportunities abound. Yen Press just shipped its second volume of Twilight: The Graphic Novel, with a 350,000 copy first printing (see “Twilight: The Graphic Novel”).  And games are available from Scene It (the DVD/trivia game) and Cardinal (board games).