An interesting area of research in religion is the role of the woman in various religions, historically and today. How in the world did it happen that many of today's major religions place women in a lesser role? As a subset of that topic, there has been extensive research done on a group of nuns, published maybe ten years ago. This was a health study, but an interesting example of how a religious life can influence us in many ways. Another prospect for research is some recent interest in the connection between religious experience and our brain chemistry. Yet another area which might be of interest is what religious actually is. How do we distinguish between a religion and a cult? Can a cult become a religion? In today's political climate, there are any number of interesting ways in which politics and religion mix, with Mormon candidates and an Islam Center near Ground Zero, people burning the Qur'an, and so on.
It seems to me that research in religion must focus on some tangible aspect of it, for example, sociology, psychology, or history, since religion is, by definition, a matter of belief, and no research in the world will ever establish the "truth" of a religion or the lack thereof.