Two new blogging initiatives well worth informing you about.
One is the fast-growing LawProfessorBlogs network (US). Have a look at their homepage for an overview of the participating profs and their subjects. No comparative law or constitutional law as of yet, but many traditional subject areas (contract, property) and some more exotic ones (chinese law, elder law and white collar crime, to name a few). All the blogs are updated very regularly (how these people find time to do anything else besides is a mystery to me!) and could be a good standard blog-reference in your field of interest.
Since September 26th, the University of Chicago's School of Law has been maintaining a collective FacultyBlog. Have a look here for posts by faculty members, including professors Levmore, Stone, Sunstein, Posner (2x) and Nussbaum. For a taste, you could check out professor Cass Sunstein's discussion of a recent US study finding a predominance of Democratic (left-leaning) faculty among US law schools, from the perspective of the phenomenon of 'group polarization'.