Some of the major improvements:
- Shader tracing. The documentation is lacking at this time, but it appears as if it will be possible to retrieve information about registers.
- Logical operations on a render target. Direct3D has been lacking this functionality for quite a while (glLogicOp in OpenGL), so it is nice to see it arrive to the API.
- More powerful resource copy routines. It will now be possible to copy from one subresource into itself, even if the regions overlap.
- Up to 64 UAVs can now be bound to the pipeline. Even more exciting, UAVs can now be used from any pipeline stage. I am already thinking of what could be done with a UAV in the hull/domain shaders...