I'll be honest: it's a very good trailer. Martin Freeman is a perfect Bilbo and hearing the dwarves sing "Over the Misty Mountains Cold" is a pleasure. On the other hand, I still don't like the look of the dwarves, especially Thorin, and, maybe I'm just looking for things to complain about, but the brief scene between Gandalf and Galadriel didn't sit well with me at all.
In short, I expect The Hobbit movies will be much like The Lord of the Rings movies -- feasts for the eyes that are at their best when they hew closely to Tolkien than when they deviate from him. I also expect that most gamers, like most moviegoers, will care not a whit about textual fidelity.