Mary Hodder at napsterization.org (via Ulises Mejias) states that simply counting links isn't as important as the nature of the links in determining influence.

For many bloggers the relevant sphere of influence is not overall popularity, as those indexes express. It's influence and connection within a community. And the relevant measure of connection isn't the number of connections -- it's the depth and impact of those connections. This is about celebrating the niche, and measuring engagement over time."

She gives a much more complex rubric for determing a blog's importance.