Quote from: Blizzard (Source)

• 4-piece bonus on all season healing sets (Redemption) has been changed to “Reduces the cooldown of your Hammer of Justice by 10 sec.” to “Increases the healing from your Holy Shock spell by 30%.”
• Paladin Season 1/2 Retribution gear now now has resilience (Gladiator’s Vindication, Merciless Gladiator’s Vindication).

• 4-piece bonus on Restoration-spec Arena and PvP sets has been changed to “The casting time on your Healing Touch spell is reduced by 0.25 sec.” (In 2.3 it was a 15% increase to outdoor movement speed.)
• 4-piece bonus on Balance-spec Arena and PvP sets has been changed to “Your Wrath casts have a chance to reduce the cast time on your next Starfire by 1.5 sec.” (In 2.3 it was a 15% increase to outdoor movement speed.)

• 4-piece bonus on Season 3 set has been changed to “Reduces the cooldown of your Blink spell by 2 sec.” (In 2.3 it was a 0.15 second reduction to Polymorph casting time.)

• 4-piece bonus on Vengeful Gladiator’s Thunderfist now Gives you a 50% chance to avoid interruption caused by damage while casting Lightning Bolt. (In 2.3 it was 70%.)