Guillermo Del Toro and Peter Jackson confirmed (talking to to Empire Magazine in honor of the publication's 20th birthday) that 'The Hobbit' will be two films.This should put to bed the theories that one film would focus on The Hobbit and the second would be a bridge film to the Lord of the Rings trilogy.
Del Toro: "We've decided to have The Hobbit span the two movies, including the White Council and the comings and goings of Gandalf to Dol Guldur."
Jackson: "We decided it would be a mistake to try to cram everything into one movie. The essential brief was to do The Hobbit, and it allows us to make The Hobbit in a little more style, if you like, of the [LOTR] trilogy."