A look at the trailer reveals some of the new features of the game. These are some of the things I noticed while watching

 

00:09 - A loadout of the characters.  There's a "Proficiency" slot that looks like it says kick. Then the second loadout graphic shows the new Strike Package option with this character using Assault.  Also, there are new killstreaks, but that's to be expected.  

 

00:17 - It looks like phones will be doing all the work of calling in air strikes.

 

00:58 - Dog tags are now dropped when you die.  I'm sure the accumulation of dog tags will be tied to different in-game milestones.  Maybe it's replacing the betting you could do in Black Ops.

 

01:04 - Another loadout.  The proficiency this time is Focus.  A new piece of equipment is show, the Bouncing Betty.  Second strike package, Support is shown, along with more killstreaks and new perks.

 

01:22 - The Bouncing Betty in action.  Should be far more deadlier than a claymore.

 

01:55 - The 3rd layout.  Can't really tell if there's no equipment, but can't really tell.  More killstreak and perks are shown, including a killstreak called Ballistic vest that does make me wonder how that will work.

 

02:12 - It looks like a new cope that that gives you more precise view of the enemy.  

 

02:45 - A new robot/moving turret i shown.  Not sure if that will be like the RC car of Black Ops or if it works on its own.

 

02:59 - Another loadout.  This time the Proficiency is Attachments.  The secondary weapon is a sniper rifle, but that does go with the Overkill Pro perk.  For this loadout, the strike package is Specialist and the killstreaks seem to be different.  It looks like the killstreaks unlock more perks rather than the more traditional killstreaks.

 

03:15 - A new turret that appears to shoot down rockets.  My guess is that its use is to keep helicopters and other air assistance from being shot down by the other team's rockets.

 

03:25 - Did the turret just destroy itself?

 

 

I'm sure there's more to the trailer that more seasoned Call of Duty players will be able to point out, but those are some of the main changes to the game that I've seen.

 

Reaction from gamers, so far, has been underwhelming.  For most, it's simply not enough changes from Modern Warfare 2, but this is only the first trailer for multiplayer.  We'll have to see what else will be revealed in the next 2 months until the release of the game on 11/8/11.