It seems obvious to me that Bezos took this one public so early to garner public support so that the FAA can't just sit on it forever. All of Amazon's other initiatives didn't need some federal regulator to OK it before they could start selling it. I think this is an effective solution to getting a notoriously slow agency to move on an item. No one wants to be seen as stopping innovation, not even the FAA.
That has been my experience. I don't deal with them directly, but we have people on our team who work closely with them when it comes to unmanned aircraft.
The FAA has a comprehensive publication about UAVs: http://www.faa.gov/about/initiatives/uas/