Filming was completed on The Hobbit in early July, but at Comic-Con a couple weeks ago, Jackson mentioned possibly shooting more footage.
With the adaptation now in the editing phase of production, a report in the Los Angeles Times suggests Jackson believes there is enough material for a trilogy, especially with the appendices to The Lord of the Rings.
If a third Hobbit film is green-lighted, it would require additional footage, which also means making arrangements with the actors, such as Martin Freeman and Ian McKellen.
The first film, The Hobbit: An Unexpected Journey, will be released in December, followed by the second, The Hobbit: There and Back Again, in December 2013. A third film, if decided on, it would probably be released in 2014.