People regularly ask me what I read on the Web for these Evangelical, Catholic and Muslim trends. The SSRC just published a study of the top relgious blogs, where most people are getting their information, which gets the most hits, and which have the most authority. For those looking to to expand their blog horizons, it is worth looking at the list. The article itself is less interesting for those already online.
Here is a discussion of how to judge what is on top- authority, hits. But at he bottom it has the blogs arranged by topic: Academic, Cultural, News, Political. It also has a list of which blogs get the most comments.