In an interview with Total Film magazine, The Hobbit director Peter Jackson talked about the differences and challenges of directing The Hobbit compared with The Lord of the Rings trilogy. The article isn't online but SpoilerTV has scans here and iO9 summarized the key parts (below).

"The Hobbit is very much a children's book and The Lord of the Rings is something else; it's not really aimed at children at all. I realized the characters of the dwarves are the difference. Their energy and disdain of anything politically correct brings a new kind of spirit to it. And that's why I thought, OK, this could be fun!"

"That was something I worried about. I imagined 13 guys with long hair and beards and I thought, 'How are we ever going to know which dwarf is which? It's an ensemble from hell really. I thought nine members of the Fellowship was a problem; but here, with Bilbo and Gandalf, we've got 15. It's working out fine though. The dwarves give it a kind of childish, comedic quality that gives us a very different tone from The Lord of the Rings."

"I want it to seem like we've gone back on location into Middle-earth; that these two movies feel like they belong at the beginning of the other three. We're the same filmmakers going into the same world."

PJ On The Challenges of The Hobbit. There are any PJ On The Challenges of The Hobbit in here.