There are rumors that Sony's upcoming A77 DSLR will have an OLED viewfinder with 3 million pixels (more than double the pixel count in the current A55/33 LCD viewfinder). The new viewfinder will also have a faster refresh rate and better brightness (which is to be expected from an OLED micro display...). It is said that the same viewfinder will be used in next-gen Sony NEX cameras, too (as an optional external EVF or a built-in one, it's not clear).
This is not the first we hear of Sony's OLED microdisplays: back in January 2011 Sony unveiled a 3D head mounted display with two OLED microdisplays. Those displays were said to be made by Sony and feature 720p (1280x720) - which means 921,600 pixels. This makes us wonder whether the 3 million pixel count in the rumor is correct. After all, even eMagin's highest resolution OLED microdisplay (the SXGA OLED-XL) offers only 1280x1024 resolution (1,310,720 pixels). Perhaps (as some commenters suggested) these are 3 million sub-subpixels - which fits 720p more or less.