The film will open with DD's funeral, before the scene with the Death Eaters/Charity Burbage (confirmed to be in the film as Burbage has been cast. Also, I think they'll include some of the scenes at Hogwarts described by Neville in the book i.e. Ginny, Neville and Luna trying to steal the sword and the Carrows punishments. I've heard that part one is ending when the trio are caught by the snatchers, which means that there will be plenty of action in both filmsw, and the Battle of Hogwarts will have plenty of time given to it.