That was a helluvah trailer, for sure. I love those kinds of trailers/commercials where it's just soft music, and most everything else does the talking. Few if any words of dialogue spoken, just letting the trailer speak for itself.
Let's hope the actual game is as compelling as the trailer, eh?
Apparently, from the 9+ page thread in the Off-topic section, it's drawn some slight controversy from the gaming media, with some people (mainly gaming parents) saying that they're just drawing on the controversy of a dead child, and while I can understand that, I'd have to say the trailer was a success taken that into account.
EDIT: And after watching the trailer a second time, again I say; damn. It actually makes it even more heart breaking because I realized that the little girl turned into a zombie, which is why she jumped her father and then showed why he threw her out the window.
Techland, you better not fuck up. According to the Wiki article, it's supposed to be open world, 4-player co-op, with an emphasis on melee.