That sounds like a good selling point for anyone who already owns an EV. We're going to see a big shift in how people utilize and monitor their electricity use and more people will adopt this technology as it becomes cheaper. The powerwall/solar panels are a pretty big investment.
powerwall/solar panels built into new homes makes it easy to absorb the cost along with financing to retrofit a home with it. at least in the short-term it will add value to homes and become a selling point