Ok, I can't tell you how awesome the book Tomorrow, When the War Began is. Well, not as well as the trailor for the movie can:
I don't see that this has a U.S. release date, so no idea if we are even going to see it here across the Pacific, but here's seriously hoping.
Whether we do or not, take what you just saw there, and translate it into a hold for the first in the Tomorrow Series by John Marsden. That trailer is EXACTLY like what's in the book. At least, it's how I saw it all in my head. I can't tell you if the rest of the movie will live up to it, but I'm loving what I've seen so far. The audio cd version is pretty excellent too.