The issue of how (if at all) to regulate political comment and advertising on blogs (and the Internet in general) has been coming up in many countries as the electoral cycle catches up with the blog explosion. In Australia, the last election produced threats to regulate blogs and other Internet comment on political matters, in particular by requiring identifying details to be posted[1].
This was one of the subjects addressed by the Joint Standing Committee on Electoral Matters Inquiry into the Conduct of the 2004 Federal Election and Matters Related Thereto. I made a submission attacking the idea, and arguing that only paid advertisements should be subject to this requirement. Amazingly enough[2], the Committee agreed.