I believe that by the end of the third season, there will be at least 2 Deaths. This number could be as high as 5 depending on when they decide to do the prison assault.
The two characters I see dying by the end of this season regardless of the assault would be Beth and Judith.
Beth does not really do anything except for give Carl funny looks, and for Judith I think it was a blessing to the group, but another way for Rick to snap which would make him more of a "Ricktator"
For the other three that will be cut loose by a prison assault
I would say those would be: Ben, Allen, Sasha, Axel, and Carol
Ben and Allen are just stand-in characters. They are more than likely not needed and will be picked off. Sasha on the other hand, could turn into a more developed character but will probably die saving tyreese at some point or Michonne will at least slap the crap out of her. Axel will die because he is just as useless as Ben and Allen, and Carol will be dead due to the show having to lose a main character to "amp up the tension."
I could also see Milton, Caesar, and Haley all dying to anger the Governor, but we will have to wait and see.
What do you all think? I know this is drawn out blog entry, but hey it is my first one ever, so some feedback would be appreciated... Thanks!!