Unsurprisingly, I bought the book yesterday as soon as it came out. I'm about a third of the way through, and even though he's preaching to the choir with me, I'm really enjoying it. While I'm familiar with the arguments, Dawkins writing is, as always, elegant and imaginative, and he makes genuinely thought-provoking points. He pulls no punches here and makes sure that he is not only including the God of the Old Testament (whom he calls "the most unpleasant character in all fiction") but all the gods that theists and deists believe in. He explains why some things that people call gods don't really deserve the title, and why he disagrees with many of his atheist colleagues who "bend over backwards" to avoid offending people's religious sensibilities. (He doesn't even go easy on the agnostics!)
One point which I found enlightening was Dawkins easy dismissal of the intelligent design movement. Their argument is essentially that everything that looks designed must have a designer, the universe looks designed, therefore it has a designer. He turns it on his head with the statement that anything complex enough to be a designer has only ever been observed as the end product of a slow evolutionary process.
I highly recommend this book (or at least the first four chapters), but I am all too sadly aware that many of those who stand to learn the most from reading it never will.