Screenwriting bloggers don't talk about the blogosphere. They talk about the scribosphere. (It's the screenwriting sub-blogosphere.) Kathy Sierra's harassment hasn't been all over the blogosphere. It's been all over a blogosphere. Everybody in the Web tech blogosphere knows about it. Nobody in the scribosphere does. Nobody who blogs on Myspace about their dates and their clothes knows about it either.
Neither the blogosphere nor the scribosphere are spheres at all. They're networks. The metaphor is very precisely wrong. A sphere is a three-dimensional surface with all points equidistant from the center. Equidistance from the center is a very, very inappropriate feature for a metaphor for blog networks. They look more like nerve clusters.
Each specific "blogosphere" clusters around specific high-profile bloggers, and closeness or distance to these central bloggers makes for relevance or irrelevance within that particular alleged "sphere". Just as every Rails blogger knows who DHH is, every screenwriting blogger knows who Unk is. Every Myspace blogger into dance music in the state of New Mexico knows who John S. and Grant are. But to the average reader of this particular blog, all those names, except DHH, probably mean nothing.
We tend to think of the Web tech blogosphere as "the" blogosphere because Web technology people are nowhere near as deep and insightful as we like to think we are. We were here first, so our blogosphere is the blogosphere. Right? Myspace bloggers aren't real bloggers. Screenwriting bloggers aren't real bloggers. I Can Has Cheezburger? isn't a real blog.
There isn't one blogosphere. They are very many. And none of them are spherical.
The inappropriateness of the spherical metaphor intensifies when you consider the fractal, recursive nature of blogospheres. The Web technology blogosphere includes the Rails blogosphere, the Java blogosphere, the PHP blogosphere; large parts of the Perl blogosphere, the Python blogosphere, and the Smalltalk blogosphere; as well as markup language blogospheres and the Flash blogosphere; and large areas of the design, usability, marketing, management, entrepeneurialism, investment, and advertizing blogospheres as well.
It's pretty difficult to model this recursivity accurately with spheres. It's very easy with nerve clusters. Just picture the human brain.