I started a thread about this at Search Engine Watch. I wanted to make sure this was not just me... and to start a discussion on the impact of this.
So if you are reading this here add some comments at either place.
Basically I submitted a bulk list and had a bunch of my keywords turned down because the keyword was not inserted in the creatives. I know it improves CTR but sometimes you are trying a different approach - guess you no longer have control of that yourself... Yahoo! determines which are allowed to not have the insert.