@rick @Lugrim personally, the model i'd advocate for is a lot more like teamspeak's client/server model, with the open-source touch for good measure. you can bring your own client, connect to any server that speaks the language, and all of these servers are self-contained instances which host only their own data. this prioritises the community instant-messaging aspect that i admire discord for.
(as a funny aside: if it weren't for the "instant-messaging" criteria, i would just start up a forum, LOL)