Haven't seen this posted. EIZO announced some 4K displays in 24" and 31" configurations, no word on price/availability yet. The 31" variant is 4096x2160, not 3840 x 2160 like the other 31.5" 4K displays currently available.
http://www.bhphotovideo.com/explora/video/news/eizo-brings-light-new-small-color-edge-4k-monitors
http://www.bhphotovideo.com/explora/video/news/eizo-brings-light-new-small-color-edge-4k-monitors
Squeezing 4K resolution into a 24" monitor may seem like a simple process, but being able to retain 4K resolution with pixels packed so tightly together, it becomes difficult to see all the detail in the image, and as such may not be such a simple process. At this year's NAB, Eizo showed two prototype 10-bit 4K resolution Color Edge Color Calibration monitors that push the viewing resolution of smaller panels to the to the limit. These Color Calibration monitors share features with Eizo's other Color Edge Monitors, which prevent brightness and color drift, ensuring consistent display performance throughout the day. The 24" monitor offers 3840 x 2160 UHD resolution, an actual 1,000:1 contrast ratio, and it displays 99% of Adobe RGB, 93% of DCI, and 100% of the REC 709 color space. The slightly larger 31" monitor displays 4K resolution of 4096 x 2160, which even in this larger-sized panel, strains the eyesight of the sharpest observer, discerning all the highly articulated detail in the image. It offers Both Display Port and HDMI inputs, a 1500:1 true contrast ratio, and displays 99% Adobe RGB, and 98% of the DCI gamut, making these two powerful tools for working with color accurate imaging tools.