With the new option of customizing individual characters rather than just classes came a unique opportunity for Infinity Ward and Activision. Rather than have the same old play against AI mode, the studio gained the ability to be specific and have users face off against each other's squads - the characters that they've created loadouts for. In the latest trailer for Call of Duty: Ghosts which was released today, that gamemode is detailed.
"Squads lets you play a variety of new game modes with your customized squad-mates. Play solo against another player and their squad, or cooperatively with friends, competing versus an AI-controlled squad."
And the best news for all of you who like to train before they dive headfirst into the fray? All XP earned carries over into the real multiplayer. But you don't even have to do anything to earn XP, if your squad battles against other squads and wins, you'll find yourself gaining XP because of that.