I think we, as the tech community need to find ways of facilitating the needs of everyone in a way that's natural. I like the idea that I can share to Facebook (with my close friends) to Twitter (with my followers who may or may not know me in real life) and I can also see the use for Google+ and LinkedIn for sharing with professional contacts.
What does need to die however, is the overuse of social sharing buttons. I've been to way too many sites where you have a social sharing strip before AND after the article and then a floating sidebar to top it all off.
Would love to see a report from KISSMetrics / Mixpanel on how effective the various implementations of social sharing buttons are.
Edit: Said "personally" too many times
One thing this misses is the social proof aspect of the sharing buttons.