Thanks for the post!
I was hoping Maxwell can do this as well with a descrete video card (Intel or AMD CPU) - just to have more choices.
I'll need to look at AMD more closely if I want GPGPU APU to function properly with the CPU and GPU (cores) sharing the same 64bit address space. Then just wait a LONG time for software to catch up.
In the mean time, if I want this functionalty with any highish-end CPU and a descrete card, I'll need to wait a few years.. maybe this is only possible in a post PCIe ERA ! Skylake, Excavator, whatever.