I appreciate the contributions to Atheism made by Dawkins, Dennett, Hitchens and Harris. But this book demonstrates that they are standing on the shoulders of many great thinkers. Many of these people promoted atheism at a time when doing so could result in execution by the state or their murder. Our lives may be finite but the values we impart to the next generation may live forever.
Great thinkers? Have you ever read Leviathan? Hobbes is far too rigid in the framing of his arguments. That's not to say he wasn't a great thinker, but I can't help but wonder whether he actually read his own work after he completed it.
Also, while these philosophers were certainly the forerunners of the "atheist awakening" we're experiencing today, I wouldn't play down the contribution of modern activists and thinkers.