My wife wanted to go see Atonement yesterday, so we went. I thought that it was pretty good. The use of the score to connect various scenes as well as integrating the score with the live sounds in the movie was very good.
My biggest problem with the movie was the 1st act didn't spend enough time investing the viewer in the main characters' relationship. You could sense there was something there - and for a second there was something ... but as a viewer, I needed more. It made the 2nd act too easy to watch because the proper attachments weren't made in the 1st.
I do have to give kudos to either the editors or director for some of the filming in the early parts of the movie...letting you see events from the perspective of one person ... then another, without feeling like it was too repetitive.
I thought that the third act was actually interesting, and a nice way to end the movie (though I didn't read the book - maybe that was straight from it). Pretty good movie overall.