Search Engine Blog talks to Topix.net founder Rich Skrenta. Rich emphasizes that Topix strives to automate editorial functions in categorizing stories.
Recognizing named entities challenges the machine first to be able to tell whether the story cites the movie star or the ordinary person with that name, and then to understand whether the story is actually about the person or just mentioning him or her in passing (this is a big flaw in Google news alerts.)
Rich also talks about dmoz, the open directory, and says that "while directories were very interesting in the mid '90's, keyword search has eclipsed them as the main ways consumers find information on the Internet."
And my favorite quote from Rich: "Search is a first step to full utilization of a world-sized corpus of encyclopedic information, combined with the full value that community participation in the content & commerce process can provide."

A good read.