The "Atheist" Religion

Do you know what the fastest growing religion is in the United States? No it isn't the nutty Islamic or Christian Fundamentalist sects. It's the "religion" of atheism. So-called non religious people make up a growing group of American society.
Ok, I know a "religious atheist" is an oxymoron. But today's atheists are a different breed from their predecessors. In short, atheists are those who believe in reason alone, in those things that can be arrived at through intellect and the scientific method. Concrete evidence for the existence of a God, they argue, just does not exist.
They believe one can live a happy life based on the human ethics that were developed, not from a God handing down a tablet of commandments, but rather through a natural evolutionary process. For most atheists today, it's not just denying the existence of God but a passive practice of that "faith". In many ways they are more like humanists who substitute man for "God" than true atheists.
And they know that they are one minority in society that is very much vilified by the believers. In America, atheists are not very well thought of, and it's still acceptable to criticize their non belief in a ..uh..not so polite way. People may have negative views about Jews, Muslims, Catholics or other religious sects, but they know they are not supposed to voice their views. But it is still socially acceptable in the U.S. to say anything one wants about atheists. So it isn't surprising that atheism in America is a silent movement?
Yet, in a poll by the Graduate Center of the City of New York University, the population of people who describe themselves as "non religious" more than doubled fro 1990 to 2001, from 14.3 million people to 29.4 million people. The only other groups to show such growth are the other extremes- Fundamentalist Muslims and Christians.
Could it be that the extremes are pushing the center outward? But doesn't this religious split mirror the split in other areas of our society? Is not the middle (old way) being shoved aside by the two extremes? And is this a good , bad or neutral change? You tell me.