Everything seems normal with CTR and RPM, my concern is something seems up with page views, they seem to be cut lower each month and hence CTR rises. Earnings are still good. I have a concern about the page view issue and to be honest can't think what is wrong, the views are down from my own estimation but the sites are performing well in search engines.
Are people spending more time on twitter and facebook rather than searching Google? I really don't know the answer, but can't complain from a CTR, RPM or earnings issue. I honestly can't see the fasination with twitter or facebook, but there is a saying "Simple things please simple minds".
IMO Google are playing this business setup right and have very clever people working for them, I think time will bring the results back to Google.