One of the diseases that Breckinridge Scott mentions as a typical "scare" in the US is Ebola, which would have a large outbreak less than a decade after the book was published, and which did cause a scare in the US that was very much disproportionate to the chances of anyone in the US getting it.
It's stated in one chapter that the Ukrainian government relocated to Crimea during the war. How'd that work out, huh?
Barack Obama is implied to be the "first choice" for Vice President of the bipartisan war-time U.S. government, but is passed over in favor of Howard Dean. Two years later in the real world, Obama is elected President of the United States.
The soccer mom makes reference to her daughter being a fan of Jamie Lynn Spears, wearing soccer cleats with her brand on them. Just one year after the book came out, Spears' career was destroyed by her teen pregnancyscandal.
Paul Sorvino as Fernando Oliviera in the audio book, discussing organ transplants from infected donors.
Breckinridge Breck Scott would come across as a darkly hilarious parody of the pharma bro Martin Shkreli if you werent aware that WWZ was written almost a decade before the latter achieved national infamy by massively hiking the price of his companys pharmaceuticals.
Magnificent Bastard: Fidel Castro, even more so than in real life. When it was clear his country was turning against him, he gave up his position and endorsed the new institution, essentially becoming the father of the new government, and a national hero.
Memetic Mutation: Mark Hamill's clipped delivery of "Die, motherfucker, die!" in the audiobook.
Paranoia Fuel: The premise of a zombie apocalypse and the all-too-realistic depictions of our governments failing to handle it is enough to keep you awake for a very long time.
In-universe and out example: The possibility of a zombie shambling around that somehow slipped through the cracks of operations like the Battle of Hope or the large scale urban cleanups. The above-mentioned catacombs of France? How likely is it that there are still a few zombies shambling around in there? Or in a dense forest somewhere? And what's to stop it from making it into a populated area at the worst possible place and time.
Or, if you live in a coastal area, a massive horde of zombies can just come shambling out of the water at any time, which is likely considering there are millions of zombies wandering the ocean floor.
In relation, all of North Korea. No one knows what happened to them. Even decades later, no one's interested in finding out. Or rather, they want to know, but there's no answer that isn't extremely terrifying.
Squick: A lot. Particularly the descriptions of "digested" human remains found inside the zombies. And the infection-by-organ-transplant vignette.
What an Idiot!: The actions required for the Battle of Yonkers go beyond mere Hollywood Tactics and into such mismanagement and bad decisions on every single level of command that it requires the entire US military to be lobotomized. Simply the basic premise (filming a live battle to look cool for propaganda purposes) is completely against the standard operating procedure of the military, and that's just the tip of the iceberg.
Angst? What Angst?: Tommy doesn't seemed to be upset at all when his parents became infected.
Harsher in Hindsight: The Garbage Truck scene, It was filmed in George Square, Glasgow, only a year later in the same place, at christmas a man driving a Garbage truck blacked out and plowed through a crowd of people, killing several.
Narm/Narm Charm: Some people found the literal waves of fast zombies climbing on top of one another to be very dramatic and scary, others thought that it just looked silly.
The behavior of the zombies either comes across as creepy (as it is the case for most of the film) or laughably over-the-top (as it is for certain parts near the end of the film).
The latter involves with the teeth chattering zombie near the end. When Gerry manages to successfully become ill to fool the zombies into believing he's terminal, the thing walks in... and makes the most awkward, dumb-looking, mole-rat looking teeth click for the longest time.
Then there are the zombies who instead of moaning or snarling, squawk like birds.
Not to mention the zombie kept in custody that has bulgy eyes and keeps banging its head on the glass wall it's trapped behind.
After that, Gerry having a gratuitous Pepsi break. Product Placement at its finest. And even if you could get over that, the fact that the vending machine is filled to the brim with Pepsi cans destroys any serious attempts at what is supposed to be a triumphant scene.
There's a scene where Gerry and co make it to their getaway plane on bikes. In-universe this makes sense, because it makes a lot less noise than walking in the rain would and it doesn't set off the zombies. Doesn't make it any less silly, though.
One of Gerry's daughters screaming, of all things, "I want my blanket!" as her father drives through the hole left behind from a garbage truck smashing through gridlock at 30 miles per hour and a horde of zombies is descending from behind them. Yes, she's probably in shock, but it's still...odd.
Squick: In the books, North Korea's fate is kept ambiguous. In the film, they manage to avoid a large-scale outbreak by pulling out literally everyone's teeth. That way, if someone's infected, it's almost impossible for them to bite someone and transmit the disease. It's unmentioned whether the higher-ups were exempt.
They Changed It, Now It Sucks!: Fans were quick to call it an In Name Only adaptation. This seems to have calmed down with the release of the film, which even the author described as so thoroughly changed from his book that there was little left to be upset by.
In particular, the zombies in the film work on a fundamentally different level than the ones in the books, completely changing the course of the story.
Uncanny Valley: Zombies don't blink. Not only is this creepy, it also means the surface of their eyes is never lubricated, leading to the eyes becoming scratched and opaque. Hence the traditional white eyes.
Visual Effects of Awesome: A prime example of story dictating visual effects, rather than CGI for the sake of CGI. Everything is practical until it's impossible to depict without FX.
Given that Dr Fassbach is a highly regarded virologist and one of the people the military are looking to figure out the cause of the outbreak, you have to question the sanity of whoever decided to send him into the field with zero combat training, rather than let other, more expendable personnel gather evidence and samples for him. Naturally, only a few minutes into the mission, he panics at the sight of the zombies, slips on the ramp as he attempts to retreat and blows his own brains out when his gun accidentally discharges. Also, who was the genius who decided to give the guy with, again, zero combat training, a gun? Yes, he probably wanted the ability to defend himself should the need arise, but seriously: if you don't know how to use a gun properly, including safety handling, you shouldn't be allowed to have one at all.
Karin calling Gerry's phone. He is on a mission in Zeke infested territory, and she's seen at first-hand how dangerous they are, and she calls his phone. Not only did she get some of the most popular characters in the movie killed, she almost blew the whole operation. You do not call someone's phone when they are on a mission like this and you don't know if they are somewhere they can safely talk. Sure, she's worried, but come on.
Gerry himself also qualifies for this, as he failed to turn his phone off when he knew he was supposed to be as quiet as possible. Hell, most people who were watching in the cinema managed to turn their phones off, and they weren't in a life or death situation. Even when he gets out alive and they finally talk to each other on the phone he pretends nothing happened and doesn't tell her not to call him again.
It does allow for some meta-humor, as Speke snarks that everyone present should have turned off their cell phones and pagers out of consideration for everyone else. Including the movie audience who did.
At the Jerusalem wall, everything goes to hell when the zombies hear the refugees singing. They only hear it because a civilian takes a microphone, and simply says "it's okay" to the soldier, who lets her sing. This is unacceptable behavior at any installation (they wouldn't let a random person take over the PA system at a Wal-Mart, let alone a secure military zone), but the Israelis know the zombies are attracted to sound.
This can also apply to whoever stood lookout on the wall and didn't notice the infected piling up until they spilled over the top. Ditto for the people in helicopters patrolling the wall who made no attempt to shoot the zombies climbing the walls until they had already gotten over.