I just bought a 13" Macbook Pro Retina. The screen is phenomenal I use it with an external monitor half the time which is almost a shame. I know on the 15" rMBP 1920x1200 is selectable as a scaled display resolution, and the max on the 13" is 1680x1050, but I just noticed when I plugged in my 1080p external monitor it gives me the option to mirror the display. On the rMBP screen itself the 1920x1080 looks beautiful, still very sharp albeit text is pretty small. Being a 16:10 screen, 1920x1080 leaves a bit of black bar top and bottom occupying those 120 pixels. I suspect if my external monitor was 1920x1200 it would fill the rMBP's screen. So, the hardware is capable of scaling to 1080p/1200p, it's just not selectable like it is on the 15" rMBP. Is there some kind of system mod that will allow me to select it? This is more for fun as 1680x1050 is plenty of desktop space and I love it.