I know that Noah's status is currently unknown, but I think that he is alive, because he could become a character that could have good character development.
I think that Carl and Noah become quite close (Well, because they're the same age and might be quite a like) but as they become closer, they become the troublemakers and basically become brothers, which also brings Rick and Karen a lot closer. They might end up kissing and they become a couple (In secret) and when Carl and Noah are out troublemaking, they stumble across them kissing! (Kinda like when Carl stumbles across Rick and Andrea)
This makes the two boys fall out because they're not happy with it and they end up fighting, then a heard brakes in, during the brawl, and Carl (Since he's becoming cold) locks Noah inside the room. When he's returning to the group, he remembers how close they were and then returns, but when he opens the door, Noah has escaped and so have half of the walkers, now Noah seeks revenge.
What are your thoughts on this?