Clocked over at Wired is another reason to diversify your traffic sources as the screw tightens on Google adwords advertisers:
http://blog.wired.com/business/2008/04/march-google-sl.html
Meanwhile Adsense rules have changed which will ahve an adverse effect on a lot of Adsense Publishers: Get your sites in check:
Read more here:
http://adsense.blogspot.com/2008/03/another-look-at-optimizations.html
