Behaviours of the Blogosphere

Suw Charman points to a new report on the growth and patterns of readership in the blogosphere - some interesting stats, even if they're fairly US-centric. I'm slightly miffed that reports such as this still tend to throw open news sites like Slashdot into the mix as if they were blogs (which clearly they're not), but then again Slashdot now offers individual user blogs in addition to its collaborative open news content, so perhaps that's why it's included here. If not, then, why are other open news sites such as Indymedia, Kuro5hin, and Plastic missing?