JenSense, again has the scoop on the new AdSense policy changes: It’s official! You can now run AdSense on the same page as other contextual ad programs
So it seems that Google tightened things a little by not allowing similar looking ads to appear on a site, but at the same time loosened things by allowing other contextual ads on the same page. Note however, the YPN’s terms do not allow YPN to be on the same page as other contextual ads, so you still can’t run AdSense and YPN on the same page.
Thanks to Jennifer for staying on top of this for us. Know we just need to figure out how different ads need to be in order to be considered different looking.