So, The Walking Dead TV show has followed the trend of introducing characters from the comics into the show every season. 

Season 1 - The Atlanta survivors

Season 2 - The Greene family

Season 3 - Woodbury survivors, Tyrese, Allen, Donna, Ben, the prisoners

So who'll show up in Season 4? Maybe Abraham's group? Father Gabriel? The hunters? Will they eat Hershel's other leg? Maybe at the end of Season 4, we could see the group setting off for Washington DC? Maybe even reaching the Alexandria Safe Zone?

Only time and various spoilers will tell...