Maybe I'm just growing up, but I see social networks as a means for many to connect without effort. While some may say thats good, I say it is the effort that makes the connection special/valuable. I still use social networks to share links + info though. [I don't mind social networks being used to re-enforce real connections]
The Twitter founders have often said their real goal for Twitter was for it to become a pervasive backbone component of the internet itself which explains a lot of the moves they have and haven't made with the website itself.