Barry covered it - I want an audio output from the Echo. I'll take either wired or Bluetooth AVRCP to my AVR (Denon). That way the Echo audio can be routed to my Klipsch reference speakers and wired outdoor speakers. Some folks have tried to patch into the Echo's internal speaker wires but none have been successful from what I understand.
Instead of using ISY network resources, I control my A/V setup (TV, Projector, AVR, Xfinity, Apple TV, Wii, Blu Ray, etc) from the Harmony Elite/Hub. With one of my echobridge emulators configured for the Harmony API I can say "Alexa, turn on the TV" or "Alexa, turn on the Big screen" and it executes the Harmony activity or individual device command. A bonus is that the Harmony wand remote AND smartphone apps are immediately updated/put in that activity for seamless switching between voice, physical, and app control.
Given that the voice control is limited by the Hue setup, I hope in the future Amazon integrates directly with Logitech. Hopefully that would give me "Alexa, mute the TV" instead of "Alexa, turn on some-word-not-including-mute-because-it-seems-to-be-reserved".