Today I made a fresh install of Ubuntu 12.10.
The vgaswitcheroo module can be used to power off the discrete graphic card and use only the integrated one from Intel. Personally, I don’t have any advantage in using the discrete graphic as the integrated one is enough to play HD video, the most GPU consuming task I ever need.
So I confirm that the solution described in this post still works on 12.10.
I edited the two files, rebooted the notebook… and then there was silence!