DC Universe Online's next major update, players will begin wielding the shield for their own superheroic (or villainous) capers. A recent interview with creative director Jens Andersen discusses the intended role of the shield in combat.
Andersen explains that while the new weapon comes along in a very PvP-centered update, it's not meant to be used specifically for PvP; the team just wants to have something new for players to enjoy no matter what. In play, shields are similar to a staff weapon, but unlike most other weapons, the shield can continue to build a combo after a heavy strike by moving back to light strikes. That should make the shield a very aggressive option -- perhaps odd for something that's not generally thought of as a weapon.