It was fantastic! A wonderful adaptation (first part), an excellent start to a new trilogy, and a nostalgic return to Middle-Earth.
Yes, it's more of a light-adventure story, with more humor, set at an earlier (I'd say more mystical) time.
I loved it, and I can't wait until December 13th 2013.
Don't listen to the critics who are WAY too judgemental here. They're trying to compare it to LOTR far more than they should.
That said, if there's one thing I didn't like it was Azog. Really cheesy, terrible rendition of the character. Should've had a real actor... or at least come up with a better, more realistic design.