Well if the season 3 trailer is anything like the season 2 one, we just watched every single second of screen time with a walker or any sort of action in it right now and there won't be anymore. I seriously would have dropped this show three episodes in to last season but its one of the few shows my wife likes that I can stand so I keep watching it with her. There were some fantastic moments here and there but I just don't think they made up for the rest of the snoozefest.
While the lack of walkers really bothered me during S2, I understand perfectly well that a show without the added human element of drama and characters will get stale and boring quickly. Unfortunately the fertile ground a post-apocalyptic setting offers for truly gritty tales about the human spirit gets ignored completely. Even in the absence of walkers there would be some great stories to tell. But instead of watching characters coping without their creature comforts and then getting desperate as food and water supplies dwindle, we just get the usual TV drama fair about personal space, lack of respect, and people not communicating well and getting frustrated with each other. It's a boring waste of potential for the only zombie-themed show on television.