Fr. Robert Barron, rector of Mundelein Seminary, has spen a lot of time debunking the arguments of the modern atheists. I think he quite correctly says that one of the problems is that they aren't really all that new. All they're doing is rehashing arguments put forth by Frederich Nietzsche (God is used by the powerful to keep the powerless from becoming self actualized) and Karl Marx (God is useful like a kind of drug: it's a delusion that stops people from realizing the horror of alienation).
Recently, atheists in Florida erected a bench with some of the more shallow religious criticisms on it. Many atheists want their views to be recognized as a religious perspective so that it can be taught in religious studies departments. The problem is that it's really not a religion inasmuch as a reaction to religion. If there were no religions, there would be no atheism. That's why you can read this story on NBCnews.com about a little boy who was killed when he fell off a float in a parade and read HORRIFIC comments from atheists. They react, oftentimes exceedingly pessimistically, cynically, and derogatorily, towards people who do believe. And, in the US, their voice seems to be getting louder and louder.
But, I don't think atheism should be considered a religion specifically because it doesn't contribute something positively to the conversation. Take the issue with the bench. This is a reaction to a 10 commandments monument that was allowed on a part of public soil. Say what you want about them but the 10 commandments are a positive statement of a way of life. Love God with your whole heart. Don't kill. Don't steal. Don't covet your neighbors goods. The bench doesn't provide a positive way of living life. It's just a reaction. Its statements are all about how God and religion shouldn't have anything to do in the world. Okay, so what should? Atheists can't tell us what they believe because they have no set of core beliefs. They only thing that unites them is not believing in something. Should we take care of the poor (Marx) or is the loss of a poor person simply part of survival of the fittest (Darwin)? Atheists can't agree. Is life essentially meaningless suffering (Sartre) or are we supposed to craft our own meaning (de Beauvoir)? Atheists are split. Should atheism erect a bench with anti-religious statements on it (those who won the lawsuit) or should they just try to get the 10 commandment monument taken off (those now critical of the "bench")? Atheists cannot agree. I could keep going but you get the point.
Ultimately, I personally believe atheism's downfall is that it is inherently pessimistic because of it's reactionary underpinnings. Atheism either says nothing to people who have lost a child or says that they are fools for seeking comfort. Religion offers hope that, despite all the chaos and apparent hopelessness, there is hope because there is something rather than nothing. Life will never be the same on earth for these parents and they deserve time to mourn and support from family and friends. But I hope these folks find comfort in the fact that the same God who made everything visible can also make something that is currently invisible where all pain and suffering is gone.