This just makes no sense. A feature the community has been shouting about for years and years (literally hundreds of posts on Google product forums), and then they actually launch it less than two months before discontinuing the product line??
Be funny if they soon release a new Chromecast that has HDMI and AUX outs; the thing that always confused me about Chromecast Audio was why it needed to be a separate thing, especially after they went to the hockey-puck with a tail rather than stick format for the regular Chromecast.
Edit: meh, no, these things are Energy Star compliant so they shut down if no VGA is connected. And they don't support HDCP.
There's guides for this, works flawlessly.