Here is I hope all the MW3 confirmed content:

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]

Sub Machine Guns

MP5

UMP

PP90M1

P90 [Lv. 38]

PM-9 [Lv. 56]

MP7 [Lv. 74]

LMGs

L86 LSW

MG36

PKP Pecheneg

MK46 - [lvl 68]

M60E4 - [lvl 72]

Shotguns

USAS 12

KSG 12

SPAS 12

AA 12 [lvl 39]

Striker - Semi-auto - [lvl 48]

Model 1887 - [lvl 62]

Machine pistols

FMG9

MP9

Skorpion - [lvl 36]

G18 - [lvl 70]

Pistols

USP .45

P99

MP412

.44 Magnum - [lvl 46]

Five Seven - [lvl 58]

Desert Eagle - [lvl 76]

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:

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]

Attachments:

Red Dot

Silencer

Grenade launcher

ACOG

Heartbeat sensor

Hybrid sight

Shotgun

Extended Mags

Thermal scope

Rapid Fire

HAMR scope

Holographic

Grip

Variable Zoom scope

Akimbo

Red Dot Reticles:

Target Dot

Delta

U-dot

Mil-dot

Omega

Lamda

Proficiencies:

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)

Breathe-Hold breath on ARs. 

Camos:

Desert

Arctic

Woodland

Digital

Urban

Blue Tiger

Red Tiger

Fall

(Gold is also confirmed)

KILLSTREAKS

Assault Killstreaks:

4 Kills - Care Package

5 Kills - IMS - 3 or 4 placeable landmines that cannot be stunned or flashed

5 Kills - Predator Missile

5 Kills - Sentry Gun

6 Kills - Precision Airstrike

7 Kills - Attack Helicopter

7 Kills - Little Bird Flock - Mini Helicopters which patrol the map

9 Kills - Little Bird Guard - Big Helicopter that follows you from above and protects you

9 Kills - Mortar team - Mortar team but with 5 predator missiles - all go off at the same time in different places

10 Kills - Talcon - Mini Tank Robot

12 Kills - AC130

12 Kills - Pavelow

15 Kills - Juggernaught Suit - From spec Ops ( for anyone who sais in the spec ops video he gets it at 14 kills, well thats because he has hardline on)

Support Killstreaks:

4 Kills - UAV

5 Kills - Counter UAV

5 Kills - Ballistic Duffel - Drop Juggernaught perk for the whole team, not jugg suit

5 Kills - Airdrop Trap - Drops a hacked care package

8 Kills - Sam Turret

10 Kills - Remote UAV - Target enemies with missiles

12 Kills - Advanced UAV - Blackbird

12 Kills - Remote Turret - Sentry Gun that you can control

12 Kills - Stealth Bomber

18 Kills - EMP

18 Kills - Juggernaught Recon Armour - Care Package Drop Armour

18 Kills - Escort Airdrop - Drops 5 care packages, one will be hacked

Specialist Killstreaks:

2 Kills - You get 1 extra perk

4 Kills - Get another perk

6 Kills - Get another perk

8 Kills - All perks

DeathStreaks:

Juiced - Lightweight - 4 Deaths

Martyrdom - 4 Deaths

Final Stand - 4 Deaths

Revenge - Last person that killed you is always visible on your mini map - 5 Deaths

Hollow-point (Stopping power for one kill) - 5 Deaths

Dead Mans Hand - You run around with c4 in your hand (suicide bomber) - 6 Deaths

Perks:

Plus = With Pro added

Tier 1:

Extreme Conditioning - Sprint longer distances + Climb obstacles faster

Sleight Of Hand - Reload faster + Faster weapon swapping

Scavanger - Reload ammo from bags + Spawn with more ammo

Blind Eye - Undetectable from air support + Faster launcher lock on and extra damage to air support

Recon - Explosive damage marks target on HUD + Bullet damage marks target on HUD

Tier 2:

Hardline - One less kill for Killstreak + Two assists count as a kill towards next killstreak

Assassin - Immune to UAV, Motion Sensor, Thermal and Heartbeat Sensor + Immune to CUAV & EMP

Overkill - Two primary weapons + Second primary can have 2 attachments

Quckdraw - Faster aim down sights + Faster animation of using equipment and throwing grenade  

Blastshield - Flack Jacket (Immune to most explosives) + Immune to stuns and flashes

Tier 3:

Sitrep - Enemy equipment is visible + Enemy footsteps are more clear

Dead Silence - Your footsteps are silent + No fall damage

Stalker - Faster movement with ADS + Delay on claymores

Marksman - ID target from range + Longer hold breath on scoped weapons

Steady Aim - Increased hip fire accuracy + Faster aim down sight while sprinting

MP Map Names:

Alpha

Alps

Bootleg

Bravo

Brooklyn

Carbon

Coast

Dome

Exchange

Hardhat

Interchange

Lambeth

Meteora

Mogadishu

Paris

Plaza 2

Radar

Seatown

Underground

Village

Hope I didn't forget anything.