After doing quite a lot of Boss Brawl games recently I have come to the conclusion that we need some system like the existing friends system for groups of people who are doing a zone together. Currently as soon as a few people hook up to redo the same zone over and over they instantly put in a friend request so they can easily rejoin the same game over and over.
I don't really want to add everyone I ever play with as a friend. Not that I'm not a friendly person or anything, I'd just rather my friend list contained people I actually want to reconnect with when I play rather than anyone who I have every played with.
What do you think about a group concept? Leader forms a group and then there is a new tab like the friends one for those in your current group. If the leader disbands or quits the game, the group folds. People can ungroup themselves and the leader can remove people from the group. Means you get the same functionality as the current friends system without filling your friends list with random people.