Dawkins' argument that the presupposition of god requires then yet another explanation of god. He doesn't realize this criticism applies to any posited ultimate cause, including physicalism. In fact this very issue forms the foundation for some of the classic arguments for God. The only way the regress can terminate is with an uncaused cause, which only can be met by a godlike being. So followed to its logical conclusion Dawkins argument proves the existence of god.

Sam Harris seems to think the problem of evil disproves god, yet most philosophers now believe it does not after Alvin Plantinga's work. At any rate, at best it can disprove a good god.

Dennett doesn't seem to have an argument, and just tried to explain away everything he doesn't believe in.

Hitchens also doesn't have an argument and relies on emotional appeals, claiming god is like the north korean dictator, the irony apparently being lost on him that north korea is a forced atheist state.

So overall the most glaring problem is lack of any argument whatsoever, which is not promising for a supposedly intellectual position. When an argument is offered it would not even pass a freshman logic class.

Prior generations of atheists were not so intellectually vapid. Anthony Flew would be a good example if it were not for his conversion to theism.

Oh one more thing, all of the besides Hitchens erroneously like to rely on computer science to support their claims. Whereas if you have a background in CS you understand they don't know what they are talking about.