This needs to happen to at least one character:
When was the last time we had someone die and then successfully turn? Not Pete, because he was killed before he could turn, and Lee was only determinant. Duck was determinant too, so it looks like the last person who died and turned was Mark.
It's the zombie apocalypse, someone needs to turn in Season 2, otherwise that would just be weird. It'd be a shocker if we see them get into a scrap with a walker, and it kind of looks like they get bit, but they hide their bite and we only find out after they turn. This could happen to someone like Nick; if Walter doesn't shoot the zombie attacking him, then it could be revealed that it bit him and he didn't realise until after they were caught by Carver. We see him coughing a few times throughout the next episode but not enough to really make anything of it. Later on he turns and more people end up getting bitten, and eventually the place goes into chaos, kind of like Crawford did.
But yeah, someone has to turn this season.