These topics are a way for Technorati to create a simpler category system for blogs they index. Technorati Topics are presented on the home page and updated dynamically as new blog posts or stories are updated on these blogs. Only content from the “best blogs” are shown in the Technorati Topics. Some of the Technorati Topics include Entertainment, Technology, Politics, Sports, Business, and Life.
What are the criteria to be consider a “best blog” and be shown in the Technorati Topics pages? Dorion Carroll explains they use a combination of “Technorati Authority, frequency of posting, use of relevant tags, links to related subject matter and general topicality.”
There is more discussion and coverage on Technorati Topics at Techmeme.