Essentially, he concedes that when religions make untestable, nonscientific claims, science is essentially agnostic towards those claims. If a religious belief is constructed in such a way that it is simply untestable, then by definition a continued belief in such an idea can only be defined as faith. His position as a skeptic is to focus on testable claims, and leave the untestable religious claims alone. Some skeptics disagree, of course, which is expected. But even as an atheist, I can certainly admire and agree with such a position.
As Steven says,
I do feel (and this is just a feeling) that the skeptical movement is most effective when we are clear about the boundaries of science and the nature of science vs faith vs religion. I prefer to give people critical thinking skills and a love for science, and not worry about their faith. It is also quite possible (again, this is only my bias, as I do not have any solid evidence to back it up) that you will lead more people away from faith by this approach than by tackling their faith head on.
I've encountered quite a few fellow atheists in medical school, but also a significant number of religious students -- and professors for that matter. Regarding untestable and nonscientific beliefs, I largely agree with Steven. As long as a person's religious beliefs do not intrude upon scientific fact or political agenda, I usually have little reason to start an unnecessary argument with them. The exception to this is when parents essentially force their religious beliefs upon their children -- in my opinion stunting their cognitive development and scientific education -- but that's for another time. But as he says, I think scientists essentially have a duty to refute testable religious claims that are abhorrently false:
People do not, however, have a right to their own facts. So when religions make claims about history or the nature of the material world, they are within the purview of science. Religions should not dictate to science, to limit its scope or its conclusions. It is also logically invalid to claim that faith is an appropriate approach to factual claims.
I'll leave you to read the post in its entirety yourself. Some of the comments are interesting too, especially with regard to how many skeptics feel they need to be very clear and delicate in their approach to religion in the United States. After all, 44% of our population believes that God created human beings in their present form 10,000 years ago.