This is a bit outdated (by internet time standard)

Vintage February 2006

David Sifry observes in State of the Blogosphere, Part 2 Beyond Search that:

• Blogging and Mainstream Media continue to share attention in blogger's and reader's minds, but bloggers are climbing higher on the "big head" of the attention curve, with some bloggers getting more attention than sites including Forbes, PBS, MTV, and the CBC.
• Continuing down the attention curve, blogs take a more and more significant position as the economics of the mainstream publishing models make it cost prohibitive to build many nice sites and media
• Bloggers are changing the economics of the trade magazine space, with strong entries covering WiFi, Gadgets, Internet, Photography, Music, and other nice topic areas, making it easier to thrive, even on less aggregate traffic.
• There is a network effect in the Technorati Top 100 blogs, with a tendency to remain highly linked if the blogger continues to post regularly and with quality content.
• Looking at the historical data shows that the inertia in the Top 100 is very low - in other words, the number of new blogs jumping to the top of the Top 100 as well as he blogs that have fallen out of the top 100 show that the network effect is relatively weak.
• The Magic Middle is the 155,000 or so weblogs that have garnered between 20 and 1,000 inbound links. It is a realm of topical authority and significant posting and conversation within the blogosphere.
  

As you can see it only takes at least 20 inbound links to become an "authority" in anything. Does that mean that if all 2.7 billion links that technorati is tracking were shared equally among actual and potential bloggers, you are looking at 135 million experts?