This is all updates done since release
Call of Duty: Modern Warfare 3 Update History (All Platforms included)
TU1: Enabled Theater, Vault, Private Match options, Elite and Facebook functionality for Launch Day.
TU2: Fix for YouTube video upload on SD TVs. Matchmaking Improvements.
TU3: Theater Improvements (Fix to FF and RW in Theater), LAG improvements, Improvements to Hot Fix system.
TU4: Change to address hitching and lag in gameplay.
TU5: Further improvements for hitching and addressing lag in gameplay.
TU6: Additional improvements to address lag. Fix for Melee Jump. Clan Tag Validation (remove buttons from clan tags). Improve Host Migration logic. Prevent stat loss when player loses connection from server (Internet pull / drop).
TU7: Improvement to address "Host Disadvantage" / "Lag Compensation" that caused hosts with good connections to be hindered. Plus ability to hot fix additional tweaks based on user feedback to this change.
TU8: Networking enhancements, Theater improvements and fixes, Further improvements to "Host Disadvantage" / "Lag Comp", Increased speed of YouTube uploads from 32k to 256k, Nerf to all Akimbo weapons (reduced fire rate), Shotgun re-balance (Slight nerf to Striker, slight buff to all other shotguns, bar the AA-12 and 1887), Fix that prevents some users from not receiving their prestige token after prestiging, fix stat bug that retains "games played" stat across prestiges, removal of StealthnBomber radar visibility in Color Blind mode.
TU8: has been released on PS3 where it also includes improvements to voice chat.
TU9: 400 new ranks included in 5 new prestige levels. Also adds the ability to view Clan Rank on player card in-game when enlisted in a clan on Call of Duty: Elite. (This update is now available on Xbox Live and will be available on PSN on Feb 28th.)
Ability to select country flags as clan titles.
Additional network optimizations.
Additional ELITE push to game CaC validation.
Support for ELITE Clan Operations end future features.
Fixed PM issue where failed invites were preventing large parties from congregating.
Repair of writing of the games played field of the player stats so we can sweep LBs and correct averages on the backend.This process will commence shortly.
TU9/10 PS3: Two TU's due to Sony sub - first for Sony to test DLC, second to enable DLC on 28th.
Xbox TU9 features.
Voice volume slider fix.
HD rendering for PS3 theater.
Host migration update.
Anti lag balance adjustment for 1/2 bar connections vs. 3/4 bar connections
(Xbox) Anti lag balance adjustment for 1/2 bar connections vs. 3/4 bar connections
Additional anti-lag tuning
Host migration threshold tuned further
Fix crash in theater related to MU removal
Additional theater functionality/stability fixes
Fix for elite assists stat tracking
DLC Collection 1 release and all associated code changes.
Emergency TU (Xbox):
Security fix to prevent all current know game hacks and mods including stats revert.
TU12 (PS3) 1.6.424.1
Support for DLC Blackbox and Icebreaker SO missions
Dead Silence/Sit Rep Pro functionality fix.
PS3 countdown timer fix.
Double Repear call in glitch fix.
Release on Elite MP maps Foundation and Sanctuary.
Double Reaper call in glitch fix.
Hot Fix Updates (Released):
No Recoil glitch
Infinite Laptop killstreak glitch (Stealth Bomber Glitch)
Map Exploits (Getting into trucks, under maps) Fix
Prevent Slow-mo and Super Fast lobbies
Fire rate normalization for Assault Rifles with undermounts
FMG9 Re-balancing (Nerf)
Akimbo FMG9 Re-balancing (Nerf)
Type95 Re-balancing (Nerf) - Reduce hipspread.
Fix for ACR with Red Dot / Shotgun
Fix Type 95 bug related to dropping it.
Fix map exploits on Dome
PS3 Hitmarker Sound
Adjust direct impact damage a Semtex does to a Juggernaut (No longer 1 hit kill)
Improvements to "weighted matchmaking" to improve games for regions with low populations.
Improvements to the Spawn Logic and Spawn System.
Fix for the any Proficiency on any gun exploit.
Fix for the MG-36 grip fire rate.
Update to Infected game mode settings to remove map monkey exploits and update rule sets.
Return of Drop Zone to the Community Playlist.
Demolition spawn system adjustment.
Additional Akimbo weapon re-balancing.
Release of HC FFA and HC HQ PRO modes in Advanced playlist (errors to be corrected at 2am PST Sun 26th)
Consolidation of Elite game modes.
.11 Further adjustment to akimbo weapon fire rate.
Map exploit fixes for Infected
.12 Fixed Reaper permanent Air Space Full issue.
Recon perk: fixed issue where flash grenades weren't triggering markers.
Re-balance of LMG
Fix to prevent viral propagation of hacks.
Leaderboard averages correction.
Restoration of hacked player stats.
Re-balancing and Updates currently in Development and/or Discussion:
Party match-making adjustment to base session selection on location of party host.
Further improvements to network performance.
Further improvements to the Spawn system.
Dead Silence/SitRep Pro functionality fix. (Xbox)
MP music volume remix.
Default :30 Round Start timer for System Link only, while looking into adjustable timer for System Link games for Competitive Play.
Options to allow System Link players to 'unlock all' for competitive play in System Link only