In part two of my preview, I'm going to take a look at the perks system in MW3. Lots of interesting changes have been made to the perks, some new stuff, some old stuff coming back.. and some shuffling. Lets take a look.
Here's the list taken from another site, my input is in brackets. "+" is the Pro version and its effect. My comments are in brackets.
TIER ONE PERKS
Blind Eye - Undetectable by air support and sentries. (formerly cold blooded - but note you are not invisible to UAVs)
+ Launchers lock-on quicker. Extra bullet damage versus air support and sentries. (its nice for the support player, but other than that, the good stuff is in already given.)
Scavenger - Resupply from dead enemies. (standard stuff we're used to)
+ Start with increased ammo supply.
Extreme Conditioning - Sprint for longer distances. (formerly marathon - no longer unlimited sprint though)
+ Climb obstacles faster. (that is a nice addition, especially climbing boxes, low walls etc)
Recon - Explosive damage paints the target on the mini-map. (new perk, very interesting, definitely a team player's perk - not sure how long they enemies stays painted though)
+ Bullet damage paints the target on the mini-map.
Sleight of Hand - Faster reloading. (This is standard for COD, but interesting that its now a teir 1 perk)
+ Swap weapons faster. (This used to be scout pro in Black Ops, and SOH Pro used to be faster ADS instead - definitely a balance mod here)
TIER TWO PERKS
Overkill - Carry two primary weapons. (classic COD4:MW perk making a comeback - used to love running sniper rifle and an AR)
+ Supposedly two attachments for secondary. (but what if you aren't running that profficiency? maybe its not just attachments, but you get to use a profficiency with secondary?)
Assassin - Undetectable by UAV, portable radar, thermal, and heartbeat sensors. (the other key part of cold blooded makes an appearance here)
+ Immune to CUAV and EMP. No red crosshair or name when targeted. (Very.. Very useful, lots of people running counter UAV during the event given the general lack of map knowledge. Plus I hate not knowing whats going on in the mini-map such as positions of other teammates.)
Blast Shield - Increased explosive resistance. (this used to be a peice of equipment back in MW2, I did not use this too much since you had to enable it back then, but flalk jacket perk in BlackOps was quite useful)
+ Resistance to flash and stun.
Quickdraw - Faster aiming. (The other part to the old sleight of hand perk)
+ Recover from equipment and grenade usage quicker. (Very useful!, so many times I've been caught throwing something in these games.)
Hardline - Killstreaks require 1 less kill. (standard stuff)
+ Every two assists count as a kill towards your killstreak. Deathstreaks require one less death. (interesting additon, definitely makes this perk more useful in Pro form.)
TIER THREE PERKS
Steady Aim - Increased hip fire accuracy. (standard stuff - interesting move to 3rd perk level though)
+ Weapon is ready faster after sprinting.
Dead Silence - Move quietly. Reduce the effects of Recon. (formerly ninja perk)
+ Supposedly no fall damage. (interesting, formerlly part of the commando pro perk)
Marksman - Identify enemy targets at longer range. (so there's a limit to how far names will show up on screen?)
+ Longer hold breath. (aka iron lungs or scout)
Stalker - Move faster while aiming. (this is new, good for people who like to ADS a lot, more tactical like I presume.)
+ Delay enemy Claymore explosions. (used to be bomb squad / sit rep iirc)
SitRep - Detect enemy explosives and tactical insertions. (unchanged from before)
+ Louder enemy footsteps. (interesting move of this effect to this particular perk, used to be ninja pro, or dead silence pro).