Major Changes Are

1. you can put adsense search and referral ads on pages without content.
2. you can put adsense on error, registration, and thank you pages.
3. you need privacy policy on the site with says cookies are used to get some info.
4. you can show more than one adsense ads from more than one account on same page.
5. you can now run contextual ads from other companies like yahoo on the same page.