I'm very close to pulling the trigger on a natural gas powered emergency generator for my house, since our neighborhood has lots of big trees and above-ground power lines. The newest generation of those generators have Ethernet jacks on them. It would be awfully nice if they could converse with the Nest to maintain a power budget (e.g., don't run both AC zones at once to make sure we stay under the generator's power budget). At least in theory, this API could make such a hack possible. Hmm.