True, but people posting comments could post copyright-infringing material. Then again, they don't get money from that (unless it's spam, I suppose).

You should look at European laws (as should all the European citizens rightfully protesting stupid politicians)... For private blogs, the current process still will apply. I'm not even sure, if it does today include the provider privilege (which basically favors commercial platforms today), thus already enforcing moderation (or selling out discussion to disqus, etc). Also, people today could run around posting extremist propaganda in comments, which makes moderation necessary. As the result of this, most private (german) blogs I know are already implementing human content filters, e.g. post by email.