Hopefully the screenwriters are a bit more skilled with characterization and dialogue than Kirkman (I have to say, second time reading, there is some really atrocious dialogue).
In an odd way that's what I've found so appealing about The Walking Dead. In many ways it is a cackhanded mess, with stock characters, dire dialogue, truncated stories and shoddy contrivances - but then so is real life. Kirkman and Adlard just keep plugging on, abusing their cast in the most horrible ways imaginable, even as the cast do the same to each other, and somehow that makes more sense than the neat clockwork of an Alan Moore story, the compressed twistiness of a Morrison or the heart-warming bromances of an Ennis. It's all too easy to imagine that this is what it would be like, chaotic and cliched at the same time. As Spock might say, it's very human.
I don't want to sound like I'm not digging the Walking Dead at all - because I am, immensely. It's great escapism, real zombie fanboy wet dream stuff...
Here are my complaints with the writing (bear in mind, all of the following induces eye-roll reactions rather than 'this is shite' reactions - I mean c'mon, I have a huge Italian zombie film collection, I eat this stuff up like our living dead friends munch flesh):
Repetitiveness: For example, during the siege of the prison, the Governor replies in response to a query about the tank: "we can't fire it, so-n-so barely learned how to drive it, it's just for show" and not two pages later Machinonne says: "they can't fire that, it's just for show". This happens quite often throughout the series.
Over-expostion: This killed me during my reread: 1) a character will describe what needs to be done, we'll see the action and then the characters will talk about what they've just done or 2) characters, especially when they are first introduced, reel off huge chunks of monologue in supposed bouts of "character-building". This makes me feel that Kirkman just doesn't quite trust his audience to fill in any gaps in the story, that he sort of forces characterization (we often get an information overload about a character and then he/she sort of fades to the background for awhile) - or maybe Kirkman is in love with his own words. In any case, a very smart scriptwriter can tell three stories within a strip by using dialogue, captions and pictures and, while I'm not saying Kirkman can't do that, he just doesn't.
Sounds juvenile at times: Carol and Tyreese, both adults, "break up" (not "split" or "move on"), Rick tells Lori they "broke up", the children's dialogue has a forced innocence to it, and so does much of the "love" stuff. To me it sounds as if a 13-year-old wrote sections of the script.
Anyway, I'm not trashing the comics - I really like them - and heck, I'm buying them. I just thought I'd clarify what I meant by atrocious dialogue. I am looking forward to the series just like I look forward to reading the comics!