Today, Yahoo! introduced their new Publisher Network, a "new self-serve platform that will provide small- and medium-sized web publishers with easy access to yahoo! advertising and content." In other words, it's a direct alternative to Google AdSense.
The program, which the webmaster community initially caught wind of nearly a year ago, is currently invitation only. It's a program that I would love to participate in, if I could ;) Unfortunately, I don't have much more information to share at the moment. Are you listening, Yahoo?!