The Walking Dead may be a zombie drama, but as the latest season has proved, other people (I'm looking at you, Mr. Governor) are probably more of a threat to the survival of the human race than the walkers. However, show producer Gale Anne Hurd recently spoke to IGN and revealed that the threat of the undead is set to increase in the coming seasons, admitting:
Yeah, I don't think that in a show that goes from season to season -- we are living in a zombie apocalypse, we're living in an apocalypse where we know that unless someone has brain trauma, they're going to come back. Regardless of how they die, they're going to turn into a zombie. So I think it would be a good bet to say that the zombies become more threatening in seasons to come...I think we've come to discover that in a post-zombie apocalypse you can never get too comfortable with anything.
Excellent news! More zombies can only be a good thing. Perhaps the group will come into contact with a herd, because the only thing scarier than a one walker is a ton of walkers.