I think the Hobbit has a chance to be a better movie than the LOTR movies. The book translates to film better, IMO, because you have one linear story (instead of the two stories in LOTR), and there isn't as much going on in the Hobbit. I think part of the problem with the LOTR movies is that the material they needed to cover was so vast. Large parts of the story were simply ignored, and many modifications were made to the original books and, to me, most of these modifications made no sense (hey, we were chilling out in Rivendell, but we heard you were in trouble at Helm's Deep, so even though it took you 3 months to get from Rivendell to Helm's Deep, it took us about 12 hours.)
It will be interesting to see if the Hobbit is different in tone/look than the LOTR movies. I kind of hope so, but I doubt it.