I haven't read Marvel Zombies yet.. I'm waiting for the trade paperback which should come this summer. Basically Marvel contracted Kirkman to work his zombie magic in the Marvel universe, where all the superheros are zombies. Looks totally hilarious.
I thumbed thru one of the issues at the comic shop and it showed the Silver Surfer coming to warn the Earth about the coming of Galactus, but instead all the Marvel characters immediately tried to eat him. ^__^
Also check out Invincible, under Image Comics. It's Kirkman's greatest work ever. I argue it's even better then Walking Dead.
30 Days of Night has five volumes: The original and offshoots titled
Dark Days,
Return to Barrow,
Bloodsucker Tales, and
Three Tales. I agree with you though, the stories aren't that fleshed out and there's no character development, etc. They are basically short stories with a peculiar artist style that it refuses to deviate from, even if the stories suffer from it.