Most of us who bought the previous models were under the distinct impression that a future OS upgrade would let us switch without logging in/out, and that we could take advantage of the unused dedicated GPU for other stuff as well.
I don't personally recall seeing anything to support this. Can you expand on who/what gave you that impression, in case I just missed it?
The article suggests that this is both a hardware and software solution, so that it would be impossible to add to older hardware not specifically designed with these new techniques in mind:
"...because Apple is unique among PC vendors in that it controls both the hardware and software."
"NVIDIA's Optimus is another solution to this problem. It uses a combination of hardware and software to enable automatic switching between integrated graphics and a discrete GPU."
