At long last some real details on MW3 Multiplayer! there's so much to take in here its not funny. So far I can see nothing I dont like except now I have to choose between a tactical insertion and a flashbang

But I do like that claymores and grenades are in the same category so this should mean less claymores around the place. There's a new game mode called Kill Confirmed where you have to recover the enemies dogtags to claim the kill, if not you lose it. This should encourage short/medium range gun on gun action which should be great.
What really sounds great is that you can also choose a proficiency for your gun like reduced recoil, less sway or better range. Class customisation possibilities will be huge with this extra option.
Anyway everything I've found is listed below, enjoy
It's confirmed that the game will have complete customization of private matches just like in Call of Duty: Black Ops where you could adjust the settings and preferences with the ability to save and share. Rather than the ability to create your own emblem, Modern Warfare 2's player card returns where you'll be able to unlock and use pre-made emblems and titles. The game will launch with 16 maps and there are a total of 28 Killstreak Rewards.
There is at least one new game mode called "Kill Confirmed" where you have to kill an enemy and then collect the dog tag that they leave behind. If you don't collect the dog tag, then the kill can't be confirmed and you won't score any points for your team. The enemy has the ability to reclaim the dog tag, thus preventing you from scoring any points.
Impressions:
The game feels and plays like Modern Warfare 2
Interrupting reloads is still possible
Dropshotting is slower than it used to be
Quickscoping feels to be the same speed as MW2
Gun damage is comparable to MW2
When being shot, the flinch will often lead you into a headshot (if shooting the enemy at the same time)
The maps are big with many paths, but very little environment is climbable
There are still quite a lot of places to hide and/or create choke points despite 402's original statement
There are 80 levels in each Prestige but nothing else is known about the Prestige system at this point.
Assault Rifles
M4A1
M16A4 - 3 round burst
SCAR-L
CM901
Type 95 - 3 round burst [lvl 32]
G36c - [lvl 42]
ACR 6.8 - [lvl 50]
MK14 - Semi-automatic [lvl 60]
AK-47 - [lvl 68]
FAD - [lvl 78]
LMGs
L86 LSW
MG36
PKP Pecheneg
MK46 - [lvl 68]
M60E4 - [lvl 72]
Shotguns
USAS 12
KSG 12
SPAS 12
Striker - Semi-auto - [lvl 48]
Model 1887 - [lvl 62]
Machine pistols
FMG9
MP9
Scorpion - [lvl 36]
G18 - [lvl 70]
Pistols
USP .45
P99
MP412
.44 Magnum - [lvl 46]
Five Seven - [lvl 58]
Desert Eagle - [lvl 76]
Sub Machine Guns
MP5
UMP
PP90M1
P90 [Lv. 38]
PM-9 [Lv. 56]
MP7 [Lv. 74]
Sniper Rifles
Barrett .50 Cal
L118A (bolt action, looks similar to the L96 from Black Ops)
Dragunov
AS50
RSASS [Lv. 44]
MSR [Lv. 66]
Launchers
SMAW
Javelin
Stinger - [lvl 40]
XM25 - [lvl 52]
M320 GLM - [lvl 64]
RPG - [lvl 80]
Lethal
Frag
Semtex
Throwing Knife
Bouncing Betty - [lvl 37]
Claymore - [lvl 53]
C4 - [lvl 69]
Equipment
Equipment
Flash
Concussion
Scrambler (like a Jammer)
EMP (hand held grenade version)
Smoke
Trophy System - [lvl 45] (basically a tripod sensor that deflects explosive sent in its direction)
Tactical Insert - [lvl 61]
Portable Radar - [lvl 77]
The Riot Shield also makes a return to Multiplayer.
Perks
Perks are once again in 3 Slots and will all be unlocked at different levels. Pro Variants are listed in the Brackets.
Slot One
Extreme Conditioning - Sprint Longer Distances (climb obstacles faster)
Sleight of Hand - Faster reloading (faster weapon swapping)
Scavenger - Locked until lvl 39 (unknown)
Blind Eye - Undetectable by air support and sentries (Launches lock on faster, extra damage to support and sentries)
Recon - Explosive damage shows targets on minimap. (Bullet damage shows targets)
Slot Two
Hardline - One less for killstreak (2 Assists count as one kill towards streak and 1 less death required for death streaks)
Assassin - Immune to UAV, Portable radar, thermal and heartbeat (Immune to Counter UAV and EMP and no red cross hairs)
Overkill - Locked until lvl 47 (unknown)
Quickdraw - Faster ADS (Faster recovery from equipment and nade usage)
Blast Shield - Increased explosive resistance (Immune to stuns and flashes)
Slot Three
Marksmen - ID targets from long range (longer breath holding)
Sitrep - Detect enemy explosives (Hear footsteps louder)
Dead Silence - Locked until lvl 55 (unknown)
Stalker - Faster movement while ADS (Delay enemy claymores)
Steady Aim - Improved hipfire accuracy (Faster ADS after sprinting)
Attachments & Sight Reticules
The following is a list of all the Attachments and Sight Reticules that will be in Modern Warfare 3. Not all Attachments will be on all weapons.
Attachments
Red Dot
Silencer
Grenade launcher
ACOG
Heartbeat sensor
Hybrid sight
Extended Mags
Thermal scope
Rapid Fire
HAMR scope
Holographic
Grip
Variable Zoom scope
Sight Reticules
Target Dot
Delta
U-dot
Mil-dot
Omega
Lamda
Proficiencies
New to MW3, each primary weapon can have an additional "perk" assigned to it. These are unlocked along side attachments for the guns as you level up your weapons:
Kick -Reduced recoil
Range -Increased range
Attachments -Equip 2 attachments to the weapon
Focus -Reduced flinch when shot
Melee -Faster melee
Stability -Reduced sway
Impact -Great bullet penetration through walls (like deep impact)
Speed -Faster movement w/ weapon equipped
Damage -Shells do more damage (Shotgun only)
Death Streaks
Death Streaks are returning from Modern Warfare 2
4 Deaths - Juiced - Faster sprinting for a short period when respawned
5 Deaths - Revenge - Reveals the position of the enemy who killed you at all times
4 Deaths - Final Stand (Lv. 32)
4 Deaths - Martyrdom (Lv. 51)
5 Deaths - Deadman's Hand (Lv. 57)
5 Deaths - Hollow Points (Lv. 71)
Strike Packages
This is the new name for Killstreaks and they are divided up into two different categories - Assault and Support Packages.
Assault Package
3 - UAV
4 - Care Package
5 - IMS - Bouncing Bettys immune to disruption devices
5 - Predator Missile
5 - Sentry Gun
6 - Precision Airstrike
7 - Attack Helicopter
9 - Strafe Gun - Call in 5 helicopters to strafe and attack for a limited time
9 - Little Bird Guard - Control a mini chopper to attack and spot enemies
9 - Reaper - Air-controlled Predator Missile x5
10 - Assault Drone
12 - AC-130
12 - Pave Low
15 - Juggernaut - Gain advanced armor package for a limited time
17 - Osprey Gunner - Be a gunner of a helicopter that drops care packages for teammates.
Support Packages
4 - UAV
5 - Counter UAV
5 - Ballistic Vests - drop a crate of armored vests for teammates to pick up
5 - Airdrop Trap - A care package which will explode when picked up by the enemy team
8 - SAM Turret
10 - Recon Drone - Controllable UAV to detect enemy positions
12 - Remote Turret - Manually controlled Sentry Gun
14 - Stealth Bomber
18 - EMP
18 - Juggernaut Recon
18 - Escort Airdrop - An Osprey helicopter delivers and defends multiple care packages to teammates.
Specialist Package
Choose 3 extra Perks which will unlock in order every 2 kills. 2 kills - 4 kills - 6 kills. Once you reach 8 kills without dying, you will gain every perk. Once you die, you lose every extra perk and must restart from 2 kills once again. Multiple attachment and multiple primary Perks may not be selected for the Specialist Package
Gun Camouflage
These return from Modern Warfare 2 and are the same as before.
Desert
Arctic
Woodland
Digital
Urban
Blue Tiger
Red Tiger
Fall