FindLaw.com has an article by Bill Gratsch of Blawg.com called "The State of Legal Blogs: A Report From the Frontlines." The article provides a brief history of law blogs and describes the different types of law blogs, including legal news blogs, legal academia blogs, and subject-matter specific law blogs:
Another indicator of the legal blogosphere's health is the continuing growth in weblogs covering specific legal subjects. Typically written by subject matter experts, these weblogs cover myriad legal topics and court cases in detail and can serve as a valuable resource to stay abreast of important developments. ....
By offering free, well-written content, often filling gaps in general legal news coverage and/or expanded analysis of important cases or regulations of the day, subject matter specific weblogs continue to grow in importance and value.