The thing that tvOS desperately needs, to my mind, is full HomeKit support. It's already a relay, sure, but when I have the Siri remote in my hand, sitting down to watch TV, frequently I want to change the lighting. If I tell the Siri Remote to dim the lights, Siri tells me she can't help with that here - please let her help! She already knows I'm making a HomeKit request, just go ahead and act on it! Why should I have to pick up my phone and wake up Siri there to handle the request?