I like Orr's book reviews, and this is one not an exception. It's a civil, thoughtful, clear, and incisive look at the philosophical problems that haunt The Moral Landscape. There are some speculations near the end that I'm not especially in sympathy with (e.g. the comparison of morality to mathematics, which I don't think can be made to work), but Orr is not committed to them - he's just considering possible alternatives.
Once again, the book has attracted a very high class of reviewers.