You were expecting something awesome and original? Pffffft horror movies are so cliche now lower your standards.
From this response, I can definitely say you should go see Cabin in the Woods and prepare to come back and eat a little crow, at least on the originality front. You might find the movie to be a big, steaming pile of horseshit, but you won't be able to deny that it's pretty original. Hell, it's about originality.