What did you think of it? I saw it yesterday, the full deal IMAX 3D 48 FPS.
I quite enjoyed it overall. It does feel very different from LotR, more light-hearted and vibrant, which I think is in accordance with the source material. For the most part they stuck with the book but gave it some mandatory big fight scenes (a bit too many in my opinion). The Necromancer side-plot is introduced a bit hastily.
Some slight spoilers after break.
My only complaint is that I think they went a bit too far sometimes. The rabbits (you'll understand when you see it), the stone giants and the later parts of Goblin-town with the swinging platforms in particular didn't really fit with the rest of the movie and the setting in my opinion. These sequences were also amongst the most CGI'd over the movie.
Apart from that it's great entertainment. Riddles in the Dark was awesome. Martin Freeman is extremely well cast as Bilbo, I think he really carries the movie sometimes and is a superb protagonist. The rest of the cast does a good job as well. Christopher Lee looks a bit tired.
The 48 FPS took some time to get used to. At first it feels like everything is sped up, but it's fine in the end. Whether or not it was worth it is up in the air.
Overall not as memorable as Fellowship was, but a good movie nonetheless.