I saw the new Hobbit film yesterday. Overall I enjoyed it, especially the integration with The Lord of the Rings and how it felt part of the same, big universe. I think the extended scenes with Radagast and the White Council added depth that went beyond the original children's tale; ultimately by the end of the third film the story should integrate well as a complete six episode tale.
My main gripe is Peter Jackson's focus on battle scenes. There were far too many. The original tale really didn't focus so much on combat as it did on running away from combat. And a related problem is that goblins and orcs really aren't that interesting as characters, so the introduction of Azog didn't help improve the story much. Whereas in The Lord of the Rings, sure the orcs were the enemy, but the real enemy was the corrupting power of the ring; the struggle was as much an internal one within the fellowship as an external conflict. I think the story will pick up in The Desolation of Smaug next year as the rivalry between the elves and dwarves develops further though. This conflict should introduce more grey characters into the story than the black and white rivalry between Tolkien's heroes and the forces of darkness. Boromir and Gollum were some of the better characters in LOTR after all.
The extension from two to three films was not a problem IMO. There's more than the enough material in The Hobbit's back story for it, and although I thought some of the fighting went on for too long, the slow introduction to Bilbo and the dwarves at the start allowed more development of their character compared to the rushed feeling that I got from the first LOTR movie. So, I think it was a good decision to turn it into a trilogy.