Windows 8 includes an updated “DirectX 11.1 Runtime” that supports Direct3D 11.1, updates Direct2D and DirectWrite, DXGI 1.2, and a revision of the Windows Imaging Component (WIC).
Portions of the “DirectX 11.1 Runtime” are being made available on Windows 7 Service Pack 1 via the Platform Update for Windows 7 Service Pack 1 and Windows Server 2008 R2 Service Pack 1 (KB 2670838) included with the Internet Explorer 10 Release Preview for Windows 7. This includes the updated components above, but is limited to WDDM 1.1 drivers on Windows 7.