JenSense reports that Yahoo has added a few new features to the Yahoo! Publisher Network interface. They have increased the channels from 50 to 100 per category and reporting URL. In addition, they have added the ability to edit and remove old color style palettes.
As an FYI - this maintenance caused a slow update of the YPN stats data. Your stats should now be live and updated. Forum coverage of these concerns can be found also at DigitalPoint Forums and WebmasterWorld.