I've always said The Road made zombie movies more acceptable, as it is so close in theme and content.
I'm a little worried at how prominent they make the mom in this trailer (only present in a couple flashbacks, as I recall, in the novel). And how they make it look more like an action film (which it definitely wasn't). I didn't imagine the psychos with southern drawls, and I think that detracts from it, by making it too specific. (As far as I could tell in the novel, you were never 100% sure they were even located in the USA, let alone the south.)
And isn't that the tunnel from the one sequence in the video game LEFT4DEAD?
That being said, Viggo looks spot on, as does the kid. I think even a competent rendering of such a shattering novel would be the high point of the year cinematically. Take that together with Zombieland, and I don't see how anyone could say zombies are through. (Since WWZ hasn't even come out yet!)