I think everybody is missing something in this conversation:
We are not building a PC. These are not PCs in shiny boxes that lots of people buy because they're stupid and could have just built their own. You cannot build an Xbone, you cannot build a PS4. Both contain custom silicon not found in any PC. Now, the usefulness of that silicon is debatable and outside the scope of this comment, but it IS there.
Given that, really want MSFT and Sony needed was CPU and GPU IP to plug into their designs. Given this, the only logical choice was Jaguar. And if you're going to AMD for CPU IP, might as well get the volume discount on GPU IP as well.
Is Excavator highly portable like Jaguar? Somewhere I heard it was supposed to be. If so, the new Nintendo console could be really awesome. Otherwise expect more Jaguar+ cores if they're smart (for easy ports).