Decentralised identity and access control. Internet single sign-on (cross domain authentication). Nomadic identity (true identity clones on multiple servers because hobbyist websites tend to kack it fairly frequently and everybody has to start over making friends with all their friends again).
Social networks which just pass messages back and forth and let you share/follow/whatever are doomed. Hubzilla may in fact be doomed but at least we aren't doing the same bloody thing as everybody else. Social networking is a very small part of what we do. You can take that away and we still have a viable project. Take social networking away from Diaspora and you've got bugger all.
But my work friends aren't your work friends. Our friend circles might overlap but they aren't the exact same. So why should you be posting to my work friends group? Don't get me wrong - I think you have an interesting concept here, I'm just trying to understand it better. (I wrote Friendika, which is kind of like Diaspora but a bit more capable - I could probably make something like this happen.).
In fact it's very much like email. You're just sending messages back and forth between people. Really, that's all it is. Most people won't leave Facebook - even if you delivered an electric shock every time they hit the FB website. It's where their friends are.
But there is room in the world for a decentralised and distributed social net. I wrote one (called Friendika). There are people who have a need for a social service of their own. There are online communities which still exist and where people send messages to each other and interact.
It is not whether or not they will replace Facebook. It is simply that Facebook doesn't cater to every social need of every organisation on the planet. Other services need to fill the gaps. One day some will realise that they are spending more time on network 'x' than on Facebook. In fact many of us are doing this today. At that point Facebook becomes irrelevant and loses its grip. Most people don't care who runs the servers. They also don't care if it is centralised or not. All they care about is communicating with people who matter. I would like to point out that girls who rejected you in high school that are now on your Facebook friend list - don't matter. If your mom is on Facebook - chances are that it is reluctantly and she'd much rather you just called her on the phone.
Social networks which just pass messages back and forth and let you share/follow/whatever are doomed. Hubzilla may in fact be doomed but at least we aren't doing the same bloody thing as everybody else. Social networking is a very small part of what we do. You can take that away and we still have a viable project. Take social networking away from Diaspora and you've got bugger all.