I'll also echo The Mediocre Pumpkin, and add my own two cents.
It's unbecoming to be concerned with what people's religious beliefs are, if they are leaving others alone, especially when atheists just want to be free to be atheists themselves. The religion clauses of the First Amendment are meaningless if the existence of religious people who aren't interested in imposing their beliefs on others cannot be tolerated. The only problem that atheists should have from religious people should also be the only problem that people from other religions should have, which is when they try to impose their religion on others. As long as religious people respect the wishes of others not to join, for whatever reason, and atheists respect the wishes of theists to hold onto their beliefs, theists and atheists of various persuasions should—I think—be able to get along.
Therefore, counting the number of theists isn't really the best measure of progress. Better would be to measure how tolerant the various groups are of each other, for example in terms of legislative agenda. For example, a decrease in legislation deriving from religious fundamentalism and a rolling back of such laws already on the books would be a definite and welcome sign of progress. The idea that social problems will be solved by everyone going atheist is a pipe dream, one reason, not the least of which, being that that will never come close to happening anytime this century.
A great deal of scientific progress has been made by theists. Sir Isaac Newton is quite possibly the greatest scientific mind in human history, but he was certainly a theist. Although I'm an open agnostic, and therefore atheistic, I recognize that a lot of people are just simply happier in their religion. Atheism isn't for everyone, and I won't be going along with any program to stamp out any and all religion, especially so long as it stays out of the secular halls of society that should be open to and work for everybody regardless of their religious persuasion, or lack thereof.