Kevin Carson is working on a fourth book! What he stresses is “a very rough draft” is available online here; it looks fascinating, as usual. 
Its topic is “the potential for networked organization to constrain the exercise of power by large, hierarchical institutions in a way that once required the countervailing power of other large, hierarchical institutions.”
(I guess releasing ongoing drafts of a work on open source is a way of achieving unity of medium and message.)