Neither Windows nor Mac OS X scale that well - too many assumptions of too many programs would be broken. Even iOS with its retina displays actually does not really scale. The reason why Apple exactly doubles the resolution, while keeping the size the same, is that iOS now treats a square of four pixels as one pixel. Oh, the text is properly anti-aliased, and you can display icons, photos and videos accurately, but the default coordinate system is still the same as on the original iPhone or iPad. That makes it easier for applications to run unmodified. Of course, unmodified apps have low-res icons, and other graphics, so they only benefit when rendering text and vector graphics. Fortunately, you can change the scaling in Quartz 2D, and optimize your code to retina displays. But you do that again by knowing what the screen resolution is, and the next step has to double the resolution again, and the programs have to be adapted again. Apart from KDE 4 and Gnome 3, no UI has made the effort to go fully scalable, i.e. using vector graphics for the icons (pixel graphics will always have scaling issues), and actually honor the dpi information of the screen (Android has screen classes, so while Android apps are not automatically scaling to whatever screen there is, the situation is good enough). So at the moment, a high-res screen for a desktop PC would be only usable on a Linux system, which probably explains why nobody is making them - the market is too small. My hope is that the new iPad puts enough pressure to make high-res screens with whatever stopgap technology you need (the iOS approach to just double the resolution, but don't tell legacy programs should be good enough for Windows, too).