"We're interested in exploring Carl as a child soldier in this war against the walkers," Mazzara said in an interview. "He becomes a very, very effective, strong part of the group. He's no longer the young child who needs to be cared for and who needs to be minded. That Carl is gone."
That tracks with the way the character has been depicted in the comic over the years; Carl gets increasingly active in the group, and becomes an essential part not only of the survival unit but of Rick's own support group following some pretty traumatic events that seem likely to happen toward the end of the show's second season.