By the time Broadwell comes out, Nvidia will shock us all and release their won competing CPU with GPU on a die and take on INtel.
Yeah I did a brief search of NVIDIA's expected implementations for Maxwell yesterday and it appears NVIDIA is attempting to do a couple similar points to which Iris Pro does as well. One of which is being able to siphon system ram if needed/in addition. Another is they're planning on adding a independent CPU unit to the dGPU, which could add an additional 10-15% CPU performance
Also Maxwell is getting more efficient of course. I think it's like 70-80% more efficient (as have most new architecture for them in the past)