I'm an atheist, and although I try to be restrained in my day-to-day personal interactions, I do dream of a world in which this belief system eventually dominates its competition. I'm not very hopeful, though. There is one threshold that any up-and-coming belief system must cross before it can hope to be embraced by a statistically significant percentage of the world's population, and atheism alone, not Islam or Christianity or Judaism or Buddhism (or even Enlightenment values or free-market capitalism or Communism or civil rights or gay rights), has yet to cross it. Atheism will never be a major belief system until it does.
(As an aside, a lot of notable atheists like Richard Dawkins or Sam Harris would probably take issue with me calling atheism a belief system, probably because they're afraid that it will afford enemies the rhetorical trick of equating spiritual faith in God with intellectual faith in the power of science. I can appreciate that concern, but at bottom, their enemies are simply correct on that point. Epistemology has pretty much established that we can't know anything for certain -- the only thing we have to go on in shaping our behavior is our belief system. The fact that we believe in gravity for excellent reasons does not change the fact that we believe in it.)
Anyhoo, here's the critical threshold: No one has ever died for atheism.
People have died for no reason other than their belief in Christ. People have died for no reason other than their belief in homosexual equality. People have died for no reason other than their belief in Communism. But there has yet to be a case where even one person, never mind a large number of people, has been put to death for no reason other than their disbelief in God or any other supernatural creator.
Nothing impresses people more than ideological death. It gives other believers something concrete to rally around, to whip the base into action. It generates public sympathy for the believers (not so much in the case of deliberate martyrdom, but certainly in the case of hate crimes, which are nearly as good). In economic terms, it allows a belief system to accumulate emotional capital through public and private investment. Like it or not, it is a non-negotiable precondition for ideological maturity and large-scale market penetration.
This presents a problem, because atheism is the one belief system that explicitly discredits martyrdom as one of its tenets. Those who believe it are the least likely of all people to be enticed by rewards in the afterlife. ("72 copies of Religulous and The Selfish Gene await you in heaven!")
This puts me in an awkward position, because while I certainly hope no atheist ever dies solely because of his atheism, I also can't help but acknowledge how helpful such an occurrence would be to the movement as a whole.
On some level human beings recognize that if an idea is worth repressing, there must be something to it. Despite how some atheists may feel about prevailing social attitudes toward them (and there is a sizeable body of literature out there that can be reduced to "I'm an atheist, woe is me"), what we experience is merely mild distaste or faint bewilderment -- nothing that remotely approaches repression.
The closest thing to repression that atheists experience in this country is the realization that no honest one among them will ever win public office. Unfortunately, humanity doesn't measure repression in political opportunity cost -- we measure it in blood.