I'm going put put my two cents in, and say that a platform capable of replacing Facebook for discussion and community on the web has already been created.
It's called Reddit.
Bear with me here, I realize this is probably an unpopular opinion.
On Reddit, all content is open -- I don't think I've ever seen a 'closed' sub-reddit available only to members. I'm not sure it's even possible.
Yet, in spite of all communities being effectively open, most sub-reddits have a strong sense of community, and are very active. Personally, I really enjoy proggit and r/math for this reason -- active discussion, community moderation, and a strong sense of community.
True. I have little interest in actual discussions on G+ or FB because of the public use of my full name, and the connections that I have there. There are, and will remain, plenty of people that enjoy interaction that has a bit more anonymity. r/truereddit is quite good.
I think part of what has happened to these dwindling forums is that they are functionally out-dated, and a bit too insular. -It takes too much time for new people to get up to speed on most boards. (dont forget Hubski, btw. :))
but you still have to register for reddit... reddit's owned by conde nast, it's not an open platform. Conde nast could at a moment's notice shut the entire thing down, or put it behind a paywall, or sell your 'likes' to an advertiser. This is a problem common to all centralised solutions.
No, you don't have to register. You have to register to post.
As for shutting it down: The code is open source, so while it'd be hard to unite around a common replacement, if they tried to shut it down it would not be the end.
This is the type of thinking that will hasten Facebook's demise. And it's a perfectly reasonable line of thought.
The next time you hear the phrase "It doesn't scale" in reference to something, ask yourself why it needs to. In some cases it might not.
Centralised approaches (e.g. websites on the open internet) obviously need to scale. Facebook is a public website. And it's on the open internet, for anyone with an account to see and ready to be hacked by those with skill who do not need accounts.
I always come back to this: How many people do you really need to be reading your profile? Friends, coworkers, family, ... potentially anyone, anywhere in the world with a computer and an internet connection? It just does not make sense.
It's called Reddit.
Bear with me here, I realize this is probably an unpopular opinion.
On Reddit, all content is open -- I don't think I've ever seen a 'closed' sub-reddit available only to members. I'm not sure it's even possible.
Yet, in spite of all communities being effectively open, most sub-reddits have a strong sense of community, and are very active. Personally, I really enjoy proggit and r/math for this reason -- active discussion, community moderation, and a strong sense of community.