Ok, so we saw in the season finale "Welcome To The Tombs" that the Governor massacred his soldiers, but Karen survived, Why did she survive? Clearly, she will have some sort of signifigance next season, as a replacement for Andrea. In my opinion she'll be the one to kill the Governor.
When Dale died, he was slowly replaced by Hershel as the group's moral compass
When T-Dog died, Oscar came in and temporarily took his role
When Oscar died, Tyreese had come into the picture just before that
We see this replacement, just before a character dies, I guess it's an easy way to tell when a character is going to die