The latest StarCraft II update is already available and it's primarily focused on co-op. The 3.11 patch notes updates introduce a new co-op mission called Dead of Night. It's based on the arcade mode Left2Die and makes players face numerous waves of enemies. The main goal is to be able to survive the attacks at night and then destroy infested structures during the day when your enemies will be unable to move.
Co-op commanders also get some changes with this patch, three who have hero-spawning masteries are being redesigned. Others have been changed "in order to make for more compelling choices" but Blizzard does warn that some powers have been reordered, so you'll need to see if your normal routine will still be the same.
The new and adjusted mastery powers are listed below. They include Zagara’s evasion, which gives Zerglings a chance to dodge attacks, and Kerrigan’s Augmented Immobilization Wave, which increases the ability’s damage.
New bundles for sale, improvements for Custom Game lobbies, and various bug fixes are also detailed in the full patch notes in this link.
New Mastery Power – Chrono Boost Efficiency: Increases the speed gained from Chrono Boost.
Unity Barrier redesigned: All friendly units gain a barrier that will block an attack or spell that deals at least 20 damage.This effect can only occur once every 240 seconds.
New Mastery Power:
– Augmented Immobilization Wave: Increases the damage of Immobilization Wave.
– Expeditious Evolutions: Reduces the cost and research time for evolutions
– Prolonged Mutating Carapace: Decreases the degeneration of shields from Mutating Carapace.
New Mastery Powers:
– Evasion: Adds a chance for Zerglings to dodge an attack.
– Sustained Frenzy: Increases the duration of Mass Frenzy.