I'd switch if I were you. Besides the power and flexibility of having one T5 headpiece available for each of your specs at level 62, Engineering gives you options to cover class deficiencies.
For example, as a paladin you have few good options for pulling mobs at range. Engineering gives you grenades and the Goblin Rocket Launcher. You have no stealth. Engineering gives you the Invisibility trinket. You have no slow fall. Engineering gives you the parachute cloak. You have no speed boosts. Engineering gives you several rocket boots options. The cooldowns of these items limit their usefulness in many situations, but I've found many powerful uses for them in PVP.
Also, Engineering gives you a new gathering skill in Outlands, Zapthrottling. You can make an astonishing amount of money off the Windy Clouds in Nagrand, and the other mote clouds aren't bad. Blacksmithing is probably the worst skill for moneymaking.