Yahoo! provides content for a variety of products and services as RSS feeds. And now it has a web page where it has collected all these RSS feeds in one page.
Visit the The Big List of Yahoo! Feeds. It has a list of the available RSS feeds from Yahoo!, all that “the Developer Network know about as well as some samples you can subscribe to. Dynamic feeds that take parameters also have links to API documentation, where available.”
For the uninitiated, RSS stands for “Really Simple Syndication” which web site developers to publish headlines and frequently-updated content as a web feed which can be subscribed to in a feed reader / news RSS aggregator like Bloglines / Rojo and developers can parse and manipulate for their own use.