Looks like it’s not just a matter of capping CPU usage and lowering fan speeds to keep that battery going now. That makes sense when you consider that the new GPU/CPU combo is doing a lot of dynamic load sharing, although it’s unclear how Apple is implementing the Hybrid GPU capabilities of the new GeForces.

You’ll have to log out after making the change, which suggests it’s changing some pretty deep processes, or possibly even loading a different driver. I hope this doesn’t make it difficult to switch profiles when you’re going from plug to battery and back.