Players looking for more people to take on enemies of Sanctuary will be able to more easily find like-minded folks via Facebook integration. Folks who tie their Facebook account to the BattleNet launcher will be able to add friends as well as see "Suggested Friends". At the moment, this functionality is available only for Diablo 3 in beta, though Blizzard has plans to bring it to other games as well.
Suggested Friends will provide users with new and easy ways to make new friends on Battle.net:
Facebook Friend Finder will allow users who have linked their Facebook account with their Battle.net account to find and add them as Battle.net friends.
Mutual Friends (Friends of Friends) will also be displayed in the new Suggested Friends section.
Recently Played With players will be gathered from recent games you have played with people that aren't currently your friends.
Currently only Diablo is supported at this