I'm calling it. If Lee's death isn't retconned. Omid will be the protagonist.
Think about it.
[*]He's apparently Clem's favorite.
[*]He's into history. Like Lee.
[*]His leg got fucked up. Like Lee's knee.
[*]He was amazed by Clementine.
[*]He can die in Episode 5, and if he does you have to restart from your last checkpoint.
And unlike Ben, Lilly, Kenny, and Molly, Omid's backstory is vague, possibly deliberate so we can learn more about him as a protagonist.
I'm 70% sure of this, lol.