someone once said that extraordinary claims require extraordinary proof. Since the existence of an omnipotent, omnipresent, omniscient god is about the most extraordinary of all claims, it should require the most extraordinary of all proof to be accepted. Therefore an atheist has no burden to disprove the existence of a god, it is incumbent upon those who do believe to convince us. I haven't seen anyone come close.
But from what I've read from the new atheists, specifically Dawkins, Hitchens and Harris (Haven't read Dennett.) they aren't trying to do that. They are trying to show the dangers and harm that religion does and disturb the notion that on balance religion is a good thing. One might disagree, but they cite example after example. They attack their theses from various angles, and thus try to illustrate their point such that perhaps one of these will resonate with the reader.
Of all of these four men, sometimes referred to as the four horsemen, a title they good-naturedly adopted for a video I saw wherein the four sit around in the same room discussing things, I think Dawkins has the best ability to speak to the masses overall while Harris' "Letter to a Christian Nation" is the most succinct example of writing.
Dawkins however has it seems adopted much more of a role than book author and professor -- he seems to be on a mission to make atheism and rational thought popular.
Dawkins has contributed much time into the creation of advertisements like the London bus ads which IIRC said, "There probably isn't a god. Now go enjoy your life."
Whether it is the efforts of people like these or other factors, the population of those who are atheist or at least non-religious seems to be rising rapidly in the U.S. It's about time IMO. Actually I tend to think the reason for the increased ranks of the non-religious has to do with the opening up of the world and the massive influx of information at our fingertips on the internet and via a wide variety of news channels etc. The more we know, the more we see the holes in our little petty human-like god that demands worship and obedience and is jealous and spiteful.