There will be high end apus with the fx branding that will at worst compete with traditional dcpus and at best destroy them, at the high end in gaming the idea is you have an apu doing cpu work on the x86 cores and offloading parallel cpu work to the gcn igp cores while your dgpu handles the display. The ps4/xbone should ensure enough market share so games developers use huma and hsa and marketshare in the mobile sector from thier hsa partners should ensure huma/hsa is used in other software.
For the first time in a long time I actually feel excited about amd but we'll see in the next 2 years what is going to happen i suppose, early hsa benchmarks look very promising.