I would be very grateful if a "Looking for Group" (LFG) feature was added. Right now I'd like to complete or revisit several group instances (Malistaire's lair, to get the last stone rose, or the Spiral Key quest, for example). I'm sure there are many other people in the same situation. Not being able to find them, however, is turning out to be an endless source of frustration.
Actually, I'm a bit surprised such a feature doesn't already exist. Something to express our interest in completing a particular quest and asking for group members (or to look for a group to join.)