I read the book a couple times now and loved it overall, but boy am I glad some of the stupid shit from that book didn't make it into this movie. Like Zombies being unaffected by most modern battlefield weapons (50 cals turn humans into ground chuck, Max), or a Battle of Yonkers scenario where armored columns get overrun, and no line of soldiers with .22s calmly head-shotting a slow-moving horde.
I really enjoyed this. I liked the changes from wide-scale to small-scale and back again. The soldiers were all badass and kewl, especially the bald Israeli chick. I'm not sure why Matthew Fox was in this except as bait for the sequel maybe, or he really wanted to be in a zombie movie, but whatev.
I would have made it a hard R, but gore isn't essential for the story this movie told, so no big loss there.
The only people I can recall actively sacrificing themselves for Gerry were US and Israeli SpecForces soldiers who were informed about his mission to find Patient Zero and/or a possible cure.
The zombies moving like an army of ants was pretty cool, actually. When the first trailers came out, I was like Huh? Wha? But it turned out to be pretty cool looking when it happened and gave the zombies a much needed level of threat that, realistically, shambling zombie hordes really don't have.
The moment he gave the wife the phone you knew it was going to ring at the worst possible moment. That was lame. His wife was irritating too. Leave it to the woman to get mugged during the apocalypse (I kid

) And his kids were so friggin annoying. I thought we'd be stuck with them the whole movie, but thankfully only through act one. I can't stand 99.99% of child actors and these were no exception. Clementine they were not.
They definitely want this to be a series and it comes across as a plausible prequel to the non-lame events described in the book. Presumably, they could then actually use a lot more of the book in future installments as the war rages on.
I give it an A and I'll be getting the DVD. Zombies are sweet!