google is now allowing us to protect our a/c by enabling to show ads only on our site dont if the feature was present earlier but certainly a new blog entry on google has highlighted the fact here is the link http://groups.google.com/group/Inside-AdSense/t/b7ea99ef96ffa894?hl=en this certainly will be of great help for us publishers
Yes. Importantly only sites listed in a publisher's approved list will have the ability to generate revenue. Update your list of approved sites now if you're an AdSense publisher. More at Inside AdSense.