The best feature is a topic popularity chart that displays the number of posts that contain your search term per day for the past 30 days. When you search, for example, for posts about the movie King Kong, you’ll see an accompanying chart on the left hand side of the page showing the relative interest in the topic within the blogosphere for the past month.
With the addition of a topic popularity chart, Technorati can be used to take the temperature of the blogosphere for your favorite topic.
Other blog search engines have such topic popularity charts, so It’s nice that the 800 pound gorilla of blog search decided to provide such a feature. Now, if they could only expand on the idea.