In an interview with the German publication c't Magazin, AMD's engineer Laylah Mah noted that the feedback-routine Microsoft used in the final specification of the DirectX 11.2 turned out to be a bit different than the one AMD anticipated and although the incompatibility lies in the driver and not in the hardware, AMD's Radeon HD 7000 series based on the Graphics CoreNext architecture might lack full support for Microsoft DirectX 11.2 API.
As you already know, Microsoft's DirectX 11.2 API will be exclusive to the upcoming Windows 8.1 OS and comes with quite a few new 3D features including the D3D tiled resources as well as HLSL shader linking, frame-buffer scaling, GPU overlay support and much more. The GPUs inside the custom APUs that will be show up in next-gen consoles, the Playstation 4 and XBox One are compatible with the requirements of DirectX 11.2 and although they are fundamentally not that much far apart in design, the custom APUs still has some advantages and can perform some tasks much more efficiently.
In any case, it will be quite interesting to see what will AMD be able to do in order to bring at least a partial support for Radeon HD 7000 series graphics cards.
Source:
Heise.de.