By June 2012, the total had increased exponentially, with blogs accounting for more than 6340 citations in law reviews, journals, and other legal publications. (The data was captured through students searches in Westlaw file for Journals and Law Reviews).
The total may, in the end, be an undercount. It is not unusual for posts on some blogs to be co-posted or republished on other blogs. This study examined only citations to the primary blog and did not attempt to assess citations to posts that were republished elsewhere.
The top 10 most cited law faculty blogs are:
Rank # of Citations Blog
1 742 Volokh Conspiracy
2 426 Balkinization
3 393 Patently O
4 279 Concurring Opinions
5 272 Sentencing Law and Policy
6 219 Prawfs Blawg
7 200 Opinio Juris
8 179 Lessig Blog
9 178 Harvard Forum on Corp. Gov.
In addition to the increase, the list has been remarkably stable. Seven of the blogs on the list were among the most cited in a similar study done in 2007. For those who want a look at a complete version of the data (including a citation list for approximately 180 law faculty blogs), it can be found at Law Faculty Blogs and Disruptive Innovation: the Data.