Basically a follow-based social graph on top of the excellent feedly experience. So there's a "Social" tab, a timeline of sorts, with things like:
"Your friend just read 'Some Cool Article Title' from 'That publication'"
"X commented on Y: ... "
"X1, X2, X3 subscribed to 'Some Publication Making The Rounds'"
Call it Socialfeeds or Feedbook or something. Bootstrap over twitter/fb social graphs.
Back in the day of google reader I remember there were some basic social features (hope these are not false memories...) and I actually really enjoyed them because of course I want to discuss all the cool shit I'm reading with my friends!