I would like to suggest that the Friends tab in the new Social window be divided into 5 categories, namely Very Negative, Negative, Neutral, Positive, and Very Positive.
This is an idea pulled right out of EVE Online, which probably has the most extensive and best information management interface I have ever seen. It essentially allows to keep note of every player's reputation in relation to you, as defined by you.
We've all encountered players who have done good actions just when we needed it the most. But we have no in-game way of keeping note of them unless we write it down somewhere out-of-game, or if we manage to record a video of it. It makes it easier for us to instantly recognise if that player is a friend or foe next time we meet them... potentially.