Windows 8 brings to the table an evolved iteration of the Windows Display Driver Model, version 1.2.

Early adopters can already test the new WDDM in the Developer Preview of Windows 8, Build 8102 Milestone 3 (M3) which has been available for download since mid-September 2011.

Itís extremely simple to get insight into just what enhancements WDDM 1.2 sports in Windows 8. Customers need only download a whitepaper made available by the Redmond company on the new Windows Dev Center.
Windows 8 Display Driver Model 1.2 Enhancements - Softpedia