Most prominent to Wine 1.9.6 is now that it better detects graphics cards using the Mesa drivers. There is also more support for Shader Model 5, C++ exception handling improvements, and a total of 32 known bug fixes. Shader Model 5.0 is what's needed by DirectX 11 support.
The better Mesa support comes from Wine now making use of Mesa's GLX_MESA_query_renderer extension, which they've mapped to WGL_WINE_query_renderer. Within the WineD3D code they are now supporting WGL_WINE_query_renderer when available for reading the GPU information. Among the information used is the device ID, vendor, video memory, and renderer string.
More details on this morning's Wine 1.9.6 release can be found via WineHQ.org.