One of the changes in Google's recent redesign was removing Google Directory from the front page. Google Directory is based on DMOZ ODP, but Google has been very slow to update their data over the last couple years. Despite rumors that Google was going to abandon ODP, it appears they're sticking with it for now.
DMOZ and Yahoo both use human editors, a solution that has obvious scalability problems. With Google's deemphasis of DMOZ, one might guess that they're working on their own automated classification of web pages, especially given their in-house expertise in this area. Topix.net has taken a similar approach and done an excellent job automating the categorization of news.