Josh Peterson at the Daily Caller notes that Martha Raddatz, the moderator of this year's vice-presidential debate, was married to Obama friend and FCC chairman Julius Genachowski.
Peterson notes that no one knows whether Raddatz ever knew Obama personally. I do not know, although I have pointed out the connection before. What I do know is that Raddatz and Genachowski were definitely a couple while Obama and Genachowski were together on the Harvard Law Review, where they were friends. And the Raddatz-Genachowski relationship was quite public -- public enough that I knew about it, despite being a year below both men on the Review and not close personal friends with either of them.
My recollection is hearing that Raddatz visited Boston frequently. I would be shocked if she hadn't met Obama at some point.
Update: I believe that Raddatz actually lived in Boston, rather than visiting, in the early '90's.