I have be thinking that it would be great to use the Rasperry Pi and Rasplex as a sort of SONOS clone...
Most of the functionallity is there, especially when you have a mobile device to act as the remote and media browser. But it would be good, not to mention faster to use, if there was a music/audio only version.
The idea would be to run a Pi conencted to a speaker and amp, and run it headless, using just the remote capability to drive it.
To make it amazing, all that would be needed then, is to have a way of grouping players together to have them all play at once. That way you could play one song out of 1, a group, or all speaker/players at once. ergo SONOS.
There is already the spotify channel. :-)
RasplexLite + Speaker + Plex/myPlex = SONOS for about $50 each and that includes your subscription. :-)
Kind regards