I think the idea would work in almost any fantasy related game; Shadowrun, for one, could be used to base this horrific reality. Using sources like 'All Flesh Must Be Eaten' or Dungeons & Dragons' 'Elder Evils' could provide some nice insight into running your own zombie game. I imagine that the start would be some plague/pox/sickness that spreads through the land as a pandemic, slowly changed the serene landscape into an overwhelming horde of macabre neophytes. Just exactly how to stop this could be the quest of long running campaign. Perhaps the ultimate goal is a very alive typhoid mary that must be purged by the Ankh of Ra.
How ever you plan to run this Festival of Blood (infamous shout) all I can say is 'C'mon get down with the sickness.'