Random male seems most likely. Clementine should make her own decisions based on what we've taught her, and i have a feeling Omid and Christa will show up, alive or dead(or undead).
Going several years into the future is an intriguing idea, but seems unlikely. As far as I'm aware the game is still based on the comics, and it's only about 2(?) years into the apocalypse in the comics, so that's probably as far as they would go.
"It's a natural instinct to fight for our own survival. What makes us human is that we fight for others." -AA:T&T