I thought about that too... if it's true (big if) maybe Sony will have to release full frame lenses for it. I'm sure they can electronically program the new body to recognize the "little brother" E-Series lenses which would then automatically crop down the sensor image to the smaller APS-C size... but allow the full sensor size for the new full frame lenses. That's IF (big if again) the full frame NEX will utilize the standard NEX E-mount bayonet.That's amazing if it pans out, I wonder what's Sony's strategy with their current range of emount lenses though as they're not made to cover a full frame sensor.
I don't think the flange distance matters when it comes to a mirrorless design. You can always incorporate more flange distance into the lens. The only limiting factor is the width of the mount compared to the size of the sensor.I'm not sure it's physically possible to keep the flange distance as it is and just 'upscale the glass' to cover the FF sensor. Then again, they might just try and slap a 1:1 aspect sensor in it and claim it has the correct diagonal