That's too bad. I know it is in the specs, I was just hoping it is something that could be changed in an update, perhaps with a firmware change. Apparently not. Thanks for letting us know.
[EDIT Added 5/5/2014: I installed Debian Jessie (testing version of Debian) on this NUC after updating the firmware to the latest version FY0032.BIO. I am pleased to report that I am now getting 1920x1200 pixels on my NEC LCD monitor ]