Here's a great NRO piece examining the zombie world of 28 Days Later and it's new sequel, 28 Weeks Later:
To understand why 28 Weeks Later is, relatively speaking, such a disappointment, it’s necessary to take another look at its predecessor. That’s just as well, because 28 Days Later is a much more interesting movie — and much more fun to write about. Easily the most gripping horror film of the last decade, the most shocking thing about its 113 minutes is quite how good they are. Sure, 28 Days Later is relentless, fast-paced, and savage, but it also displays a depth, intelligence, and lyricism that would be surprising in almost any horror movie: To find these qualities in a zombie flick is little less than miraculous.If you recalled, 28 Days Later scared the living crap out of me. I'd gotten into the a hotel late, with a 6AM flight the next morning; I was dead tired from driving and figured to watch a few minutes of a zombie flick and go to sleep. With seconds of the opening credits, my eyes were wide wide open and sleep was a long time coming...a profoundly scary movie. Sequels being what they are — the sainted Godfather trilogy exempted, of course — I don't expect much from 28 Weeks Later, but I could be surprised. I do love the subtitle of the website: 15 Gigs of Fear!