Imagine this for a twist... [minor spoilers]
 

You think you've seen it all. You called what the strangers you met in episode 2 were "up to", who was the traitor in episode 3, and even managed to guess Doug's favorite pie flavor.

But then, out of nowhere, Lee dies. The main character you've built up to your own moral standards by precariously choosing the tough decisions that the game threw at you is suddenly wiped off the face of the earth. Episode 4 and 5 are about you playing as Clem, but FIFTEEN YEARS in the future. Clem grew up adopting what she learned from Lee, and now you're the only one left of the original group, struggling to survive in a world that has become increasingly harsh.

While I actually think that would be cool... I doubt this is going to happen.

Unfortunately, the in-game screenshots depicting events from Episode 4 and 5 seem to contradict your prediction. It would still be pretty cool though

in 15 years i would imagine the world would have recovered to a point not unlike England after WWII, mostly destroyed but with the capability to build it up back to how it was, and zombies would be gone unless people still turn into zombies when they die then the only zombies would be people that die alone, otherwise it would be standard to destroy the brain of the dead, and the old zombies from when it started would be long gone, so it could hardly be called the walking dead (even if you are referring to the survivors)

Switching your main character is too jarring for a simple gimmick. If you controlled someone else, it would be for a short portion in the middle (Lee's alive) or the finale (Lee's dead).

Maybe Season 2? Though I hope they don't kill off Lee in the final episode...
But it's the end of the first season, so they could...