Windows 8 will support retina displays.

WorldWide Tech & Science. Francisco De Jesús.

Microsoft's newest Windows 8 operating  system supports a 10.1-inch tablet screen with 291 pixels per inch resolution, the company says in its Building Windows 8 blog. That compares to the new iPad with 265 ppi. 

Microsoft has frameworks so developers don't have to manually code the apps to scale. Use of standard pixel units and XAML layouts, layouts will scale. Images corresponding to each scaling percentage can be stored and appropriately named so the appropriate one for the hardware will be chosen automatically. The goal is a baseline level of quality that can be achieved with little effort.