We've been having issues getting raids together recently because of various real life schedule conflicts. Our guild leader has been playing around a bit with the schedule, but that has led to some confusion of the actual raid times. We're trying to find a way to keep track of who's available, what times, and a way to make sure we're all on the same page. Currently, we're talking about using Facebook until we get a forum up, but I'd prefer something in game.
What I'd really like is something that's a more robust version of the in game calendar, perhaps with a way to record and exchange information between players... such as time availability, character/role availability, substitute options, which 10-man is getting who, etc... Something to help ensure we're on the same page. Bonus points if it allows players to post short messages as well.