FWIW considering our current low earth orbit capabilities, which are not existent I see a trend during this down time to focus more on the science sorta background people than Aviators. That is not to say they won't focus back on aviators once the Orion Program is up and running.
I worked as a Security Police Officer at the "Cape" for a year before my current job. I know two Astronauts pretty well and keep in regular contact with them and have interacted with several. The guys operating the orbiters from the front were most always USN/USMC/USAF Aviators or NFOs then a mix of mission specialist from different places. Each of the Astronauts qualified with the T-38 talon and solo'd each one regularly regardless of who they were. There are mixed reasons for justifying this but for whatever reason I can't tell you which of the 9 stories I heard was the official reason from Nasa.