Yes, that seems to be what mine is doing as my ecobee thermostat is able to read info about peak usage times from the mains. I didn't know about the latter part though, I never imagined electric companies were making a play for the internet (though it seems like an obvious thought in retrospect).

A lot of electric companies in the US are also ISPs. They already have most of the equipment to run fiber, and many also do wireless links between substations.