One key element to debate is randomness - pg does a good job I think in describing the value of randomness in terms of random meetings, shower thoughts - etc - There are many other examples of this process at work - e.g., in management/strategy: http://www.management.wharton.upenn.edu/siggelkow/pdfs/SOart...
It bears the question - what is this valued randomness in terms of social interactions? And how can we get it in online? Definitely not chatrulette :)
But not "hackernews" type of places either - because in here we are interacting in a very structured manner - on specific topics one chooses, etc - so it's not random - we are directing our thoughts, so we are not randomly exploring things.
How can we find that great balance that physical hubs have? Going to pick up dry cleaning you find a random guy and you say hi - because you have nothing better to do you end up chatting with the guy and discovering he's Sean Parker. But that won't happen online. You just switch to another browser window that is more interesting - no need for randomness.
Is the internet killing randomness? - Or better yet: how can we come up with something that gives that value to people in a way that is not chatrullette?? It should be random but within your comfort zone, in a way that is casual and not sought after (which is uncool and weird).
I wonder what you guys think.