I read an advance copy on the weekend. (See my comments at http://www.canton.elegal.ca/archives/2006/07/#a000788 )

Chris makes the point that of the huge amount of amateur content (whether that be music, videos, blogs or whatever), only certain parts will appeal to certain people. With rare exception they are not top 40 material.

The point however is that "post-filters" such as search engines, user recommendations, reviews, and other blogs help each of us find and separate what is useful to each of us.

As far as "losing" credibility goes, my observation is that blogs started out as a form of personal geek diary, for lack of a better term. Over time they have been adopted for strategic value, and have gained credibility. Again, the issue is how we use the available tools to find the useful ones