Imagine it. Every "smart" sound system in you home is playing the same music, perfectly synchronized without any echo. Individual rooms can adjust the volume to match the conversation (or lack thereof) to meet their needs. Walk throughout your home, the music sounds great everywhere. Go out to the back yard and your wireless connected tablet / phone is feeding the same tunes to everyone out back.
Now imaging that several folks are late getting to the house but they "tune in" to your SS and instead of playing their selections from your collection they choose to listen to the "now playing" option. They are getting into the mood of your party, listening to the same music you are, at the same time you are, while they are still in route!
Partial Repost from "Jukebox on remote computer" topic because it only half fits there:
What I want is to have my SS server, with it's sound system to be controlled remotely AND to allow clients to "subscribe" to the SAME sound stream playing on the server. Other PC's in the house have very good sound systems and should be able to provide a whole home sound stage. That would be my "Party Mode".
The issue with this would be the lag / delay encountered in some clients or network connections. My answer is to allow a few milliseconds delay on the server's sound (behind the network transmission), allow the clients to adjust individually to the stream. Manual adjustment to "Echo Cancel" at each client would help in initial releases. A "Lag Window" setting on the server would allow for longer delays for higher bandwidth streams (I'm ripping everything in FLAC now but will always keep my MP3s).
Hey, users cope with transcoding now, this isn't any more difficult. Party Mode would allow you to combine all the wattage of power in the living room with the bedrooms, kitchen, den, etc. How many pounds of subwoofers do you own? Add it up and kick out the jams!!!
Sindre would need to add a disclaimer about not being responsible for the cops pounding on your door...