I think the first order of business is making the shield more prominent, for 4.0 some ideas I think would be interesting

Aegis Boon: GCD, requires block proc, no recast, does not interrupt combos (ala 2.x Shield Swipe), radius damage, heals self & nearby members, MP restore (PLD's mini Assize). Like MNK's Meditation it operates on a faster GCD.

War Drum: OGCD Radius AOE + Debuff, 30 recast, shield block procs have a 30% chance to reset it's CD