Dont you find really annoying that you cannot see if a friend of yours is playing or available for a game? Now there are just a red dot, not online, and a green one, online; having a yellow, in game, and a blue, online but away, would save a lot of pointless messaging?
I also think that knowing where my friend is, game room labeled '2v2 be good' for example, so i could join him without asking would be useful. If you are concerned about privacy for the latter thing just require consent from the added to the friend list like in MSN