It's looking like dual graphics will be the default scenario pretty soon anyway. Not in the sense of two graphics cards as in SLI or Crossfire. But more like a combination of graphics cards and integrated graphics. Both Intel and AMD are working towards their combined CPU/GPU chips (Fusion, etc.). So in the not too distant future I can see all machines having a default integrated GPU built-in. Then high-end gamers will invariably add-in a high-end GPU. So why not make use of both resources? Instead of using either the integrated graphics or the add-in graphics, use both at the same time. It doesn't have to be for graphics alone, but it could also be used for OpenCL and DirectX 11's physics engine.