Picked up the Soundtrack to Episode III yesterday.

Not too bad. It has a couple of powerful themes running throughout.
My fave is track 3, 'Battle of the Heros'.

Also included is a DVD that is a tour of the music from all of the films. It plays selected themes and plays plenty of cool clips.
If you haven't seen episode III yet, there are plenty of good clips from that film in the aforementioned 'Battle of the Heros' section.