Well I think his statistics aren't 100% verifiable. I definitely don't believe that 11 years ago, 83% of the country considered themselves Christian. This is a clear exaggeration by anyone's standards.
However, I think it's important to realize some things: Christianity isn't changing. Christianity has always had the same positions on topics (like homosexuality). What HAS changed (IMO), is the people. In the homosexual issue, people have been taught that homosexuals deserve just as much rights as anyone else, even to the point as giving them some superficial status as a race (i.e., to be against homosexuality is like being against someone's race). Again, in that example, the only thing that has changed is people's teachings on the subject. Teaching shapes the society.
As far as "hypocrisy" goes, there has always been hypocrites in every belief system. The only thing that has changed is that when someone is a hypocrite, they are particularly examined under society's microscope and lauded out like Hester Prynne, only with big "H's" on their chests. Society now looks for hypocrites so as to discredit things that it doesn't like. Christianity is now the modern example. Society is becoming anti-Christian to the point where hypocritic Christians are now thrown into the limelight to try to give creedence that Christianity is false.
Christianity hasn't changed. Non-Christianity has.