Been a bit busy, so I was unable to write about this until now. This morning, Yahoo! enabled the RSS ads feature for its YPN beta users. Some of you know that I have been beta testing these RSS ads for a few weeks now in this blog, you can check them out in the feeds or easily at one of my many feeds in bloglines under the content of the entries. Yahoo has a about rss ads page with some more information. In the ad set up section, there is a new sub section named "rss ad layout" where you can choose your publisher platform (currently wordpress or movable type only), add your rss url and more. YPN has a Ads in RSS Setup Guide with pictures and more information.
Forum discussion at WebmasterWorld and DigitalPoint Forums.