Something like a window that displays an unobtrusive temperature or forecast could be nice. But I can't imagine the market for that is huge compared to the mark

Something like a window that displays an unobtrusive temperature or forecast could be nice. But I can't imagine the market for that is huge compared to the market for TVs. Plus, windows put in place stay in place for decades, so it's a support nightmare, no chance to sell upgrades, etc. Another option would be bathroom mirrors displaying news / forecast, which is something hobbyists already implement with one-way mirrors and normal LCD displays hidden behind. At least conceptually, mirrors could become a piece of tech you "upgrade" every 2-5 years. But again, how big is that market? It could be an alternative to automotive displays. That's a big market, and it would probably look and work better than these "mirror" HUDs you can find in some vehicles today.