In order to be a "good" atheist, is it necessary to be an expert in genetics and evolution? In order to be a "good" Christian, is it necessary to be a expert historian and biblical scholar? In order to be a a free mind, do you have to write your own book?

I don't think "The God Delusion" is going to convert anyone with strongly held beliefs, although it might move some fence-sitters. Like most apologetics, it's not written for the other side. If it were, it would need a less shocking title. But as an long-time Atheist in America(tm), it's nice to see books about atheism in the front shelf in bookstores, and discussion of the topic on television. Finally, it doesn't have to be "my secret shame!"