I'd appreciate smart plugs with bidirectional communication, as real-time power use report + ability to switch the plug = poor man's way to turn most devices into IoT devices for local control. It would help in particular with ones operated by IR remotes, which deliver commands but don't get feedback on their state; you could observe device's power consumption to infer the current mode of operation, providing a bidirectional control abstraction in e.g. Home Assistant.