"Nothing" matters: 12.1% say their religious identity is "nothing in particular," outranking every denomination and tradition except Catholics (23.9%) and all groups of Baptists (17.2%).[...] Nearly 20% of all men and 13% of all women say they are unaffiliated. So are 25% of adults under age 30.[...] All the major Christian denominations are losing numbers fast. Only non-denominational Christian churches showed growth outpacing losses. "Two in three people who say they grew up as Jehovah's Witnesses have left the faith. Any one of 10 people you meet is a former Catholic," Lugo says.[...] "It will become increasingly difficult to find people who share a love for a distinct doctrine. [...] Green says he can already foresee implications in the public square as "firm beliefs and firm organizations are increasingly a thing of the past. In political life, when candidates go out to mobilize voters, they face a much more complicated picture.[...] Lugo predicts that as world religions such as Islam, Hinduism and Buddhism continue to grow in the USA through immigration and conversion, workplaces, schools and eventually the courts will face increasing challenges over religious accommodation.
USAToday, 25. February
"To illustrate this point, one need only look at the biggest gainer in this religious competition - the unaffiliated group. People moving into the unaffiliated category outnumber those moving out of the unaffiliated group by more than a three-to-one margin."
Pew Forum on religion

I was first a little dismayed to see that the numbers still were so low, but what's notable about this survey is how much things are changing, and that the losers in this game are traditional beliefs(catholic decline is only slowed down because of immigration), while the gainers are the unaffiliated.
It is also interesting that it will become much more difficult to use religion in politics, since you only end up gaining some and losing even more.