Would be pretty cool if Titans could pick up their barricades via exotic or some class ability and use it as a shield to cover friendlies from point A-B. Of course, for balancing reason they would not be able to attack and would require an animation to pick up and put down the shield. Another idea would be making class-restricted exotic weapons that are specific to each class. For example, Hunters could have a spear, Warlocks could have a staff (light/magic) and Titans could have a shield. Would make the game have that distinct MMO feel, and help give each class more depth to their identity.