A couple things of note for some of you. It appears that K-Mart has already started selling the game in some locations. If you have one nearby it may be worth giving them a call!
Secondly there was a video shown of a "easter egg" killstreak called Mother Of All Bombs or MOAB. From what I understand, it requires 25 kills with guns/equipment only but if you get it, it lets loose a bomb that kills everyone(doesn't end game), and then takes away the enemy's radar and perks for the rest of the game. Very doubtful we'll EVER see that one being pulled against us, but interesting nonetheless.