The article by Biz Stone is a take on The Wisdom of Crowds by James Surowiecki, trying to extend his observations to blogs and the blogosphere.
Obviously this is self-promotion (of blogs and the blogging phenomenon, not of the author) - in essence a survival strategy.
However, the arguments seem shaky when more closely examined. Surowiecki talks of four basic conditions for collective intelligence to outweigh individual experts:
1) Diversity of opinion
2) Independence of members from one another
4) A good method for aggregating opinions
Stone's analogy fails on conditions 2 (Independence)& 4 (Aggregation).
Except for your friends saying "You've got to blog about that!" bloggers are not controlled by anyone else.
Unfortunately, this phrase glosses over the so-called 'Blog Noise' problem:
Blogs are not independent. The aggregation mechanisms act as positive feedback within the blog community, destroying any independence but the immediate (the bandwidth effects have yet to be determined :) )
The Amazon review does mention this specific aspect: "independence keeps people from being swayed by a single opinion leader". Blogs are swayed by each other, forming a graph of many opinion leaders, sub-leaders, etc. This tight clustering of authority is detrimental to the independence of each voice: is authority used as a substitute for personal analysis and opinion?
Stone writes 'Instead of answering "How many jelly beans are in the jar?" the blog crowd is answering the unasked question, "What is worth my attention on the Web?"' Thus blogs are shown not to be a tool for answering empirical questions, but rather evaluational or subjective questions. The further likening of bloggers to neurons in the blogospheric-hivemind is closer to the truth than that of the intermediate argument presented (that of crowd-wisdom arising from blogs).
This is not to say that the metaphor cannot be applied to other network forms: Blogs (and the blog community) can be viewed as a form of genetic algorithm or effective, highly connected meme transfer. It remains to be seen whether local minima - the wisdom of blogs - can be successfully escaped in the quest for the global minimum (or maximum, if that's your sort of thing...)