Gavin Gear, Senior Program Manager at Microsoft, has posted an article on the new DPI scaling enhancements in Windows 8.1 over on the Extreme Windows Blog. Thanks to Gary V. for the link!
While high-resolution displays are amazing they also present some practical challenges. When you increase resolution you inherently decrease the size of each pixel (assuming same display size). By decreasing the size of each pixel the content shown on the display appears smaller. When display Dots-Per-Inch (DPI) gets sufficiently dense this “shrinking effect” can make content hard to see and UI targets difficult to click/tap.