Theres alot they've changed and very little has stayed the same
for starters they have put in that lovely thing known as, Money (dunno about ranks, they may have kept them but i cant remember off the top of my head), and for the emblem they've made it so we can make our own.
Money will be useful because it will allow you to by the stuff that you want to by, and not have to wait constant ages to get the gun that you are most suited too.
And the emblem that you created can be inserted onto your gun along with many different attachments, which are all customizeable, including the red dot sight which can be edited to have various shape of the sight itself, as well as the red dot that you can change colour / shape (eg have a little blue skull instead of a little red dot.)
there is the first tier perk that will change your players image, aswell as a large amount of customizeable options for the player themselves, which would mean that you wont be looking for the exact same target all the time.
Another thing that is being introduced is the online training gametype where you can be alone with a couple of AI bots and learn to get to terms with the way multiplayer works, which can help with stratagy training and helping newbies into the game without being destroyed.
there is also the wager match, where it is generally a freeforall or 1 on 1 where you can do certain modified gametypes for money, such as 1inthetube, which is a gametype where you have 1 bullet, and each player you kill you get their bullet.
In short, there is alot changing, as well as the Killstreaks that have been limited to 11 killstreaks and to make sure that the kill streak rewards dont count towards other killstreaks, so you can just get a predator strike on a small map, and destroy everything because you get up to a chopper gunner or whatever. so it's much harder but funner to use.
inferno.
