I write for teachers as a classroom teacher. I also disagree with some of the other categories. It is nice to see the list, however, if the person authoring does not really follow the blogs, they may want to be careful categorizing blogs based on the recent posts.
However, I guess it is ok to see how others view the blog.
I'm also suprised that a blog like Doug Johnson's Blue Skunk Blog isn't included on the list. (I'm a big fan!) It looks like he may not be pinging technorati which could cause problems.
This brings me back to a point:
If you're going to blog, you need to register your blog with Technorati and ping it. (See 10 habits of bloggers that win!)
For right or for wrong, Technorati is what people use to rank blogs and to be left out of Technorati will mean that sometimes you are left out of conversations that you should be included in.