(Breaking my general rule to no longer speak of zombies for a moment...)
How fitting for constantly beating a dead horde that the literary form taken is, increasingly, one of two:
fake documentary (the "found material", the survivor diaries, transcripts, fragmental verité, the forgotten but persistent, what should have rotted away but did not)
retrofitted old texts, or at least inherited non-horror genres, given "new life" (the text now declared dead - that is, common domain, open to the use of all, no longer bound to a single name, and therefore, a vitalism - in order to have a secondary plot added and to be made technically contemporary again, in terms of new copyright added and pallid mediocrity ramped up)
Apparently, the demotic spread of nonlinear narrative structural play, literary autophagy, and media-bending couldn't go fully mass, and under the sign of pulp, until it found some over-literalized figures (i.e. specific content) to latch itself onto. Pseudo-experimentation is fine, as long as you're pretending that the apocalypse has already come, and that these are dispatches from after the break, when along with the functioning of everyday life and the promise of the human race continuing, the normal novel has been gashed, infected, and apes itself wrongly across the ruins.
The turn wanted by utopian kernel hunters, and hell, why not, is just a half-step away: the zombie is a superficial effect, not the point of it. Which is only a yearning, at the heart of the most cynical repetition of the profitable squeezed stone, for concerns of formal innovation to take the upper hand. The zombie will pass, and the prospect of mass readership of things that don't go down quite so easy will stick around.
If only it weren't so obviously not so.