A few more details on the upcoming Hobbit film(s) produced by Peter Jackson, swiped from Wikipedia:
On December 18, 2007, it was announced that Jackson would be executive producer of The Hobbit and its sequel: Jackson is busy with The Lovely Bones and Tintin. Back-to-back shooting on these films will begin in 2009, and each film will be released in December 2010 and December 2011 respectively. NL and MGM will co-finance the film, and the latter studio will distribute the films outside North America — NL's first ever such deal with another major studio. Shooting will again take place in New Zealand, and Weta Workshop and Weta Digital are expected to offer their services once more. The set for Bag End and the miniatures for Rivendell were kept after production of the trilogy.
It was MGM who expressed interest in another prequel film, set between The Hobbit and The Lord of the Rings. Jackson concurred, stating "one of the drawbacks of The Hobbit is [that] it's relatively lightweight compared to LOTR... There...[are] a lot of sections in which a character like Gandalf disappears for a while. From memory — I mean, I haven't read it for a while now — but I think he references going off to meet with the White Council, who are actually characters like Galadriel and Saruman and people that we see in Lord of the Rings. He mysteriously vanishes for a while and then comes back, but we don't really know what goes on."
Sam Raimi had expressed interest in directing The Hobbit under Jackson, while Guillermo del Toro also said "it would be a privilege" to direct, having met Jackson. MGM CEO Harry Sloan said, "Neither us nor New Line would want to hire a director that Peter was not completely comfortable with." He also mentioned Jackson and Fran Walsh would co-operate on the scripts, and that Jackson may direct the second prequel as he would have completed Tintin. The actors Orlando Bloom, Viggo Mortensen and Cate Blanchett had said they would reprise their roles as Legolas, Aragorn and Galadriel respectively with Jackson, while Ian McKellen said he would like to play Gandalf: Jackson had told him, "You must play Gandalf whether I direct or not." Composer Howard Shore had also said he has thought of some themes for the film.