Pew 2014 study on religion. I find it an interesting document, especially because religion seems to be politicized in this country, and I blog about politics and religion. As an atheist (or probably more precisely, "militant agnostic"), I find the sharp rise in the "unaffiliated" category to be comforting as a probable hedge against political forces thrusting a theocracy on us. (Think I'm paranoid? One SCOTUS member has voiced the opinion that while there can be no federal church, there is no reason states can't have official churches, And polls have shown a high percentage of people who would make Christianity the national religion. I'm a regular reader of Rightwingwatch.org. I take the threat of theocracy fairly seriously.)
I find the reactions of other people interesting, as well. Because marriage equality has been a big topic of conversation lately, I find it interesting that some anti-gay politicians, like presidential candidate Mike Huckabee, and activists like Phyllis Schlafley, seem to believe that LGBT activism and especially the marriage equality movement are out to destroy the Christian church. And yet, nearly 50% of gays consider themselves to be Christian, and there is increasing acceptance of LGBT people in several Christian denominations.
I think the outright weirdest assertion on the subject of what is making all us nonaffiliated folks get unaffiliated is Bill O'Reilly's idea that it has something to do with rap culture. You know, in all of rap, I can think of one atheist rapper--Greydon Square, although he is pretty awesome. But conspicuous atheism isn't really, near as I can tell, a part of rap culture as a general rule. Despite their occasional flaws, I would credit the "New Atheists" with a good part in the "out-ness" of people of no faith. Although Dawkins, Dennett, Harris, and Hitchens and all them are not perfect and all are troublesome writers especially for social justice types--they did a lot to popularize and soften the public ideal regarding "nones". I think they helped voice arguments that people were already having with themselves, and helped make it more acceptable to have them out loud.
I also agree with Booman --the hardcore religionists are driving people away. I couldn't be on the side of any organization that contributed to human misery the way some churches seem to do.