What is the endgame for the Walking Dead?

Haven't read the comics.... wondering what the plan is for the TV show....  Do they eventually (in the next 2-3 seasons) find out what caused the outbreak?  Do they just continue to wander aimlessly through the South?  What is this show's lifespan?

In the comic books, there are over 100 issues.  So there are still plenty of untold stories. For most shows, cancellation is the endgame when ratings are low enough or key personnel want to discontinue.  Even if all current characters die, new characters can replace them.

Would people watch if this original group was all gone?  I don't know...I probably wouldn't.  

Exactly the reason I stopped watching.  I realize the entire premise is survival, but that already got stale for me.  There needs to be some sort of endgame - either a way to reverse it, or a safe place, or some history of how it started.

Topic: What is the endgame for the Walking Dead?

A weell written show can last for seasons.What was the endgame for Sopranos or Sienfield? Still one of the most interesting shows because they are original and well-written.

In an interview, creator Kirkman favors a happy ending.  This conclusion seems reasonable since the series have mostly been depressing not unlike Battlestar Galactica.