I'm a bit worried about the sequel they're cooking up. What're they going to draw from for that? Loose sketches in the appendices and questionable fan-fic?
Well, actually, the rumour based on Pjs comments are that he'd like to flesh out the Hobbit into a two part movie, putting in the White Council stuff, the Attack on Dol Guldor, young Aragorn etc...
That way they get to bring back Christopher Lee as Saruman, Cate Blanchett as Galadriel, Hugo Weaving as Elrond (well, he'd be there anyway). Also, if they do the Aragorn backstory, you have Liv Tyler and possibly a young Denethor and Theoden. Aragorn served as Thorongil with Thengel and Ecthelion during the timeline of The Hobbit (allowing for the compression of timelines).
Both Orlando Bloom and John Rhys Davies could cameo, as Gimli was Gloins son and could appear at the Battle of Five Armies, likewise Legolas as Thranduils son could appear in the Elven Kings Halls and at the Battle.
Andy Serkis could reprise Gollum, as will McKellan. They'll need a young Bilbo, who could concievably age into Ian Holm, much as Ewan McGregor did for Alec Guinness.
No, I haven't been thinking about this much at all....