Mark Bernstein has been commenting on comments on blogs (if that isn't too recursive for you). He wrote:
Comments don't belong in weblogs.
I don't agree, at least in a global way. First, I think that people are entitled to make whatever they want of their own weblog — it's their own space. Some people see their weblog as a kind of considered thinking space which they want to control quite tightly. Others welcome the interesting chaos that allowing commenting can provide. I'm definitely of the latter opinion.
Perhaps I've just been lucky — apart from comment spam and the odd childish contribution like "u smell"^1^, which I treat with the contempt and indifference they deserve, people who comment here mostly provide funny, informative and interesting contributions, and that adds greatly to this site. I suppose that if I ran a very political or controversial site, I might have more of a problem with trolls, but I still don't think that commenting per se is bad — it all depends on how well-behaved your audience is.
^1^ Actual comment, now deleted.