So far, everything looks great, and the people playing the survivors of the zombie plague are all decent enough performers. There is mystery, as the audience is still in the dark about where the pathogen came from or how it spread (I assume it's a pathogen; it often is). There seems to be a fairly large cast, which will support periodic killings, although very few had much screen time in the first episode.
There is also human drama. Grimes is searching for his wife, Lori (Sarah Wayne Callies, Prison Break), who is holed up with his former partner, Shane (Jon Bernthal, The Pacific, The Class). They believe that he is dead, so it's not really cheating, right? Although Grimes has not yet found them, previews and pictures released online reveal that it won't be long before he does. Also, one of the most moving moments from the pilot dealt with Morgan (Lennie James, Jericho) trying to bring himself to shoot his zombie-wife.
Smart writers will pull a Resident Evil, giving tidbits at a time of the backstory, and be willing to extend the universe periodically, with new directions that fit with what's come before, but still feel fresh.
The first episode of The Walking Dead will re-run several times this weekend, and new episodes air Sunday nights at 10pm on AMC.