This topic has tended to be rather abstract - let me bring it down to Earth.
In the US, Atheism is having a short period of being cool. I don't believe that this is because of anything inherent to atheism itself, however, it's a response to years of growing fundamentalist christian power. Look, the US, over the last generation or so, has become an increasingly polarized nation, with the "religious right" growing in power and the rest of the country unsure how to join the debate.
Generally, Americans have a lot of respect for religious faith, so they have been slow to look crazed evangelicals in the face and say "Um you guys are just crazy and evil!"
Im sorry kids, but I've read the bible - modern fundamentalist christianity, with its Rapture and it's love of military strength, its passion for "nuclear families" and it's embrace of corporatism.... well, I don't see all that in the bible. it's a weird, mutant, modern form of Christianity that many Americans are still kind of confused by.
I saw a poll recently where most Americans think the bible says "God helps those who helps themselves." Actually, Jesus does not say that.
And as America has weathered this storm of Christian power, they have grown tired of it.
Here's an interesting article about a book on the topic:
The authors essentially argue that Christianity is rapidly growing unpopular with young people who aren't Christians. That is, non-chrsitian Americans used to say that they had great respect for the moral stands and moral value of chrsitians - now, they more and more see christians as bigots.
Mostly, because they young people increasingly feel that Christians show excessive contempt towards gays and lesbians.
And so yes - Atheism starts to look Kewl. But as an atheist, i can tell you, atheism isn*t really kewl. It's just a reaction against what is seen, increasingly, as the mindless ant-gay bigotry of the Fundamentalist Right in America.
I expect that we'll see a more serious attempt by other Christians and other religious groups to separate themselves from the fundamentalists on this - and about time.
But for a short period, Atheists like myself will be kewl, i suppose. Not because young people are actually interested in a naturalistic worldview, but because they have come to see Christianiaty as being all about the Rapture, homosexuals, and other right wing hobby-horses.