I just learned that there is a blog concerned solely with news about blogging, www.blogroots.com.
Of course that is just the beginning. Blogdex tracks popular links, see also Daypop.com. Technorati tells you who is linking to the URL of your choice. Blogstreet.com lists the most influential and widely-read blogs. Number one is Scripting News, Instapundit is number three, the rankings are based on the metric of how often a blog is blogrolled by others. If you weight blogrolling by the influence of who is blogrolling, Instapundit is number one and Andrew Sullivan is number two.