During Breaking Bad’s Summer Finale, AMC aired 3 new trailers for Season 3. The first trailer, which is called “Darkness, we see Rick leading the group the the prison in the dark and of course they run in to zombies.
In the second trailer, which is called “Resurrection”, we hear a voiceover of Hershel talking about Jesus and resurrection from Season 2. We also see a bunch of zombies brushing up against the fence, trying to get into the prison.
The third and final trailer< which is called "Shivers, shows a certain someone dying. SPOILERS on this one if you haven’t seen the Second Season.