Carl Zeiss has been showing their Cinemizer OLED head-mounted-display product for quite some time (since 2008 in fact), but it never actually launched. They even announced a 720p version in 2010, but this one didn't ship as well. The company is now showing yet another version, this time with two 870x500 OLED microdisplays and head-tracking.
Carl Zeiss plans to release the new Cinemizer OLED in the summer of 2012 for €650 (about $850). The head-tracking will cost an extra €100. Hopefully this product will finally ship!