Hard to tell. Among people who are already here, then the answer is probably yes, but the biggest area where we see population growth is among immigrants, most of whom bring strong religious traditions of their own from their home countries. What we probably need to do is translate Mr. Hitchen's book into Spanish and Arabic, if it hasn't already been done.
In fact, I see us translating his book into every language, and flooding the world with its message. We should start a charity that starts leaving copies in hotel rooms, and airport lobbies, all with handwritten heart warming messages about the happiness we have found within.
Or not, since so many people seem so willing to purchase the book on their own, and read it, all without an army of nineteen year old MORG clones to push it.
Religion will morph to stay relevant. Atheism will probably grow somewhat, but I think over time religion will trend towards a more remote, less judgmental, more metaphorical god.
A couple of examples:
There was a time that believing the earth was not the center of the universe was a huge challenge to religion and believing otherwise was heretical. Religion eventually caught up.
30-40 years ago believing in evolution was heretical. Religion isn't quite there yet but is catching up quick.
I believe humans are pretty hard wired to believe in superstition and the supernatural. I kind of doubt that will ever change. The fad of how conceptualized will just change.
They may talk a good game, but nothing in their behavior indicates to me that they actually believe in anything resembling the traditional Jehovah.
For most people, "yes" is the only socially acceptable answer to "do you believe in God?" Like saying "good morning", the statement doesn't have to have anything at all to do with reality.