Decouple the 3D render resolution from the display resolution, meaning you can change the 3D resolution higher than the display res to get varying levels of supersampling, or lower to gain performance. This decoupling means that the UI elements can be derived from the display resolution and not be needlessly scaled. A nicer scaling algorithm can be used for upscaling, rather than the typical god-awful results we see when running our LCD monitors at less than native res. It also means that we get to play with superb image quality without resorting to driver hacks. An example game that already does this is ARMA 2.
