Perhaps, I'm the only one that would like this feature, but maybe not. Having two children under 2 years old and a wife with super hearing, watching movies at night is either a constant battle with the up/down volume buttons, or having to watch them on my tiny 7" tablet screen with headphones.
I think many a married night owls would like this feature.
Play the video on the television, but send the audio to a device. This would allow me to turn the volume up on my tablet, which my headphones are plugged into, and still watch the video on my television.
Biggest issue that I can see would be the audio sync up with the video.
Anyone else interested in this?