[zoogeny]

I think the trend of "Spiritual But Not Religious (SBNR)" is the most interesting.

I suspect a large number of people leaving religions aren't militant atheists convinced by the logic of Dawkins/Hitchens/Harris et al. Instead they are people who believe in some kind of higher power or spiritual unity in a way that is totally compatible with deism (or even light theism).

However, the traditional religions have left a lot of progressive minded individuals behind. Rigid dogmas and suspicious meta-physical commitments seem to turn people off.

This is an interesting space to explore. Many of these people would happily affiliate if there was some organization that met their needs.