There are plenty of naysayers documenting the clouds around Google, pointing out executives leaving, pay-per-click revenues flat-lining, the proposed merger of Microsoft and Yahoo, and even the possible recession as reasons why Google may not be so fantastic after all. It seems even the interest of college students in the GSOC has dwindled.
I've got to say I think its time for a Google OS. They've done what they can with mobile networks for the time being and the opportunities with free operating systems is getting better and better. Why not?