These were mine. Surprisingly
my brakes improved no end when I fitted new discs. 
Yes just like mine too. In fact mine are a bit worse. However looking at your photos it looks like the rusted surface, after the loose rust is gone, is below the level of the shiny. I had assumed mine were the opposite, the rust protruding and so was puzzled why the pads weren't hitting it. Now I look at the photos I am thinking that what has happened is the brakes weren't used much in anger, the outer edges of the inner disks were subjected to more spray as henryd mentioned, so they rusted more. Initially the rust was above the surface but as it falls away the actual corroded solid surface is below the shiny, so is never again touched by the pads, and rusts some more. A vicious circlke
Makes sense now. Not braking hard enough or frequently enough.
Did you experience any juddering under hard braking?