This picks up right where P2 left off. That shot in the trailer was your wife shooting you, in case you didn't know, and AW picks up, Saturday morning, as you wake up in the hospital. Most interesting thing right off is that, with your head wound, you keep hallucinating, making the whole place slip in and out of something that reminds me of Silent Hill, while you get attacked by angry little Gary Colemans. And yes, it just goes downhill from there.
New weaponry includes the machete (which you can throw, boomerang-like) for some nice dismemberment, the sledgehammer (which you can throw, stick-like), and the scythe (swish!). There might be a couple more, haven't finished it, yet. The added voice bits are a scream, since they are now your "mission indicators", as you have no map this time. The loss of the map is no big deal, since it's so straight-forward, it almost hurts, and Dude's comments are funnier than before. Some of the situations, too, are just great, like the Mad-Cow Tourette's Zombies (victims of the disease who shamble around, muttering obscenities), the sheriff appointing you Official Mad-Cow Relocator (which entails you wandering around, sledgehammering mad cows), and the incredibly gory Pigeon Mission (which you'll never get to see, due to budget restraints, but damn is it amazing...apparently).
Gonna be a long weekend...