My stereo is the usual rat's nest of various cables and connectors. I also have a tub full of various plugs, adapters, etc. Wouldn't it be nice to have a receiver that just had an ethernet connector on the back? Run it to an ethernet switch, and plug your turntable, TV, cassette player, into the switch?
One cool consequence is your components could be anywhere in the house, as any component could play over any powered speaker in the house.