Do a quick search on the blogs and the names of people posting comments on it. They are authoritative sources, just because it is on a blog (run by a well known complexity theorist) doesn't mean it's less important. I am quite surprised to see so many comments from these guys and such a discussion happen in public.
They don't necessarily agree with each other, though, so I'm not so sure how "authoritative" individual blog comments are (see e.g. Bradfield's followup to Jutla -- "And I don’t understand your comment about it not being known whether mu-calculus has a hierarchy of expressibility in alternation. It’s 15 years since I (and independently Lenzi) proved that it did!")
