One thing I noticed is that if you are in a group and the leader queues for LFG, you don't get an option to choose which role you want to play (e.g. Tank, DPS, Heals). As it is now, each person in the group has to go the the LFG interface and make sure the appropriate role is selected before the leader queues for the event.
So, with that said, my suggestion is to have a window pop-up when the leader queues so you can verify your role before hand.
I think this is currently causing confusion when people queue thinking they are heals when really they were selected as dps, etc...