From Killzone.com:
 

MULTIPLAYER 

Gameplay:   

• Increased the number of melee kills needed to unlock Increased Accuracy
• StA-3 LMG has had its spread increased and overall accuracy lowered
• Lowered the range and recoil of the LS-57 SMG
• Silent Footsteps has been removed as a ribbon and is now an unlockable skill
• Capturing a Capture and Hold area in Operations will award the same amount of points as it does in Warzone – it was previously worth less
• A specific screen has been added to inform players when a Skill has been unlocked
• Medic: The LS-57 SMG replaces their previously equipped StA-11 SMG
• Medic: The M224-1A LMG replaces their previously equipped LS-13 Shotgun
• Engineer: The StA-11 SMG replaces their previously equipped LS-57 SMG
• Tactician: The LS-13 Shotgun replaces their previously equipped M224-1A LMG
• Tactician: Neutralizing and capturing Tactical Spawn Areas now have two different timers, allowing you to neutralize the ownership away from the enemy faction quicker
• Tactician: Spot & Mark has been rebalanced - it will now ‘pulse’ like a sonar for 30 seconds, rather than stay constantly active during its duration
• Infiltrator: Disguise ranges for each rank has been adjusted. At rank 1, any player can see through Disguise when targeting the Infiltrator. At rank 2, a player must be within 30m range. At rank 3, a player must be within 15m range. Additionally, Disguise at rank 2 has had its timer set to ‘indefinite’ and is no longer based on a timer.
• Infiltrator: The sprint speed modifier earned from Survivalist has been decreased
• New online trophies can be unlocked from the Retro Pack DLC
• Kick-voting has been added to online matches
• Experience points earned for completing mission objectives has been increased

Clans and Squads:  

• You can no longer rejoin a clan match that has already finished
• Current clan ratings are more accurately reflected at the beginning of the match
• Players will no longer start the game in a squad by themselves
• Clan matches will no longer end in a draw if one clan quits out (therefore forfeiting) before the remaining clan is able to score points in Guerrilla Warfare
• You will no longer hang after pressing the Start button right after accepting a clan invite on the region select screen

Network Issues:  

• Network errors experienced during the open beta, such as 20002 and 8001, should no longer occur
• A 30 second time-out has been added to Multiplayer “joining” screen, should you experience an interruption in your connection
• Players that don’t have the Retro Pack, who tried joining a friend who was currently playing on a Retro Pack map, will no longer receive a network error code

General Bugs:  

• You will no longer have the “Your Faction Has Won/Lost” image roll over into subsequent matches
• You will no longer receive multiple unlock points when the server is out of sync
• You will no longer accumulate additional unlock points after everything has been unlocked
• Fixed an issue that caused the menu to stop responding after switching rapidly between the career unlocks screen and the multiplayer main menu
• The Bullet Damage ribbon reward is now applied to all primary and secondary weapons that fire bullets
• Tactician: Fixed an issue that prevented players from re-activating Spot & Mark for 60 seconds after they were killed with it active

CAMPAIGN 

Cutscenes: 

• Stutter issues stemming from cutscenes that were loaded from the menu have been resolved
• Icy Incursion: Audio is now in sync during the cutscene played while streaming into Providence Station

Gameplay:  

• Improved streaming performance for a smoother gameplay experience

GENERAL

Sharp shooter:  

• Square button is mapped to Jump when using the Sharpshooter 
• Adjusted the deadzone modifier when using the Sharpshooter

PlayStation Move:  

• Fixed a possible crash that could occur after playing the campaign while using the motion controller

Technical: 

• Killzone 3 is now integrated into the PSN store
• Enhanced security features included to deter cheating