Yahoo have made some statements about support of the 'semantic web':
The semantic web is about web pages that are structured to give search engines more specific information about what is being said. Instead of just matching words to your search terms, search engines will start to understand which web pages directly address your search, and how.
This is good news for everyone, as websites will be able to include features that bring them to the attention of users who are doing revelant searches, and users are more likely to find what they are looking for.
We look forward to hearing more in the coming months.