When Land of the Dead came out to critical acclaim in 2005, I was pleased to see George Romero, one of the great masters of horror, enjoying something of a comeback.
In fact, he was lucky to ride the zombie wave that came in the wake of 28 Days Later, Shawn of the Dead, and Zack Snyder's remake of Dawn of the Dead. At the time, gore make-up effects master Tom Savini said, "We're certainly in zombie times now!"
Trends come and go, and I figured the whole zombie thing would have its moment, then something else would come along, which is why I'm surprised they're still going strong.
We've seen them on TV commercials for Ford and Windows 7 (which nicely showcased Lucio Fulci's Zombie fighting a shark), the hit cable show The Walking Dead, and Paramount's adaptation of the novel World War Z is currently one of the most anticipated movies in production. WWZ was written by Max Brooks, son of Mel, stars Brad Pitt, and is currently being directed by Marc Foster. (The Kite Runner, Quantum of Solace.)
In the New York Times, there was even an article in the Book Review section about "the state of zombie literature," because in addition to the glut of undead movies, there've been the literary mash-ups like Pride and Prejudice and Zombies.
In the article, Terrence Rafferty went through what's become practically its own industry in literature with WWZ, The New Dead, The Walking Dead: Compendium One, and more.
As for why the undead are still among us, John Harrison, who composed the music for Romero's Creepshow and Day of the Dead, speculates, "For me personally, the appeal of the zombie is essentially they're us. George Romero's zombies have been particularly effective because he's always made sure that the zombies in his movie are not simply extras with funny make-up that are just killing machines. He's given them characters, you can identify them in all his movies, 'Oh there's the nurse zombie,' 'there's the Hare Krishna zombie."