eh theres a VERY short scene where you can see tryreese carrying a baby running away from the tank.
So there.
Judith is alive. (also he was running away from the area where rick and carl found the baby carrier and it was after he was saved from the girls so it would make sense that it would've been there where the girls put judith down.) Very subtle move AMC but ofc people are going to find it!
Also it was confirmed that the hunters won't come in until season 5 so Im guessing they will be big villians in that (seens that the governor was relatively un-interesting and wasn't in the story in the comic books for half of the time he was in the tv series).
I'd say season 4 will end with the introduction to the hunters and throughout the rest of season 4 it will be them and the 3 new characters on the road putting back together the group. Don't think anything monumental will happen though unforunately.