I would guess that that technique is not as cool as this one because VNC is probably a bit slow, whereas I assume this one isn't. Some performance figures comparing apps running on the intel vs the nvidia would be nice. The VNC technique might have an advantage if desktop effects work, though.
I think there should be another poll option. I think this is *almost* there, but still needs some tweaking so you can get desktop effects working. Ideally the intel would provide 3d by default so that desktop effects work, and nvidia would provide effects when you launch the app with vlgrun. That then would be very close to what optimus does in windoze - the only thing missing would be the ability to use TwinView for external monitors.