> determining when the user is done talking is tough.
Sometimes that task is tough for the speaker too, not just the listener. Courteous interruptions or the lack thereof might be a shibboleth for determining when we are speaking to an AI.
Yes interruptions are key, both ways. Having the user interrupt the bot is easy, but to have the bot interrupt the human will again require a model to predict when that should happen. But I do believe it is desirable for natural conversation.
