I own and have read both "World War Z" and the "Zombie Survival Guide". If you haven't, I strongly recommend you do so, both are excellent reads. But for these trailers- thank the Underdark that they are not official, since they are just pics from other movies with a voice-over. Not saying that the movie will be bad, but I hope the movie is more original than taking snapshots of "Res Evil 2".
WWZ is probably the best zombie book I've read. Please don't mess it up.