The Zombie Content Pack has been released in Project Spark, which is good news to the zombie enthusiasts- of which, there are many; zombies are certainly in vogue. And while the content pack expands the available character models in Spark, it also brings change to the free to play (f2p) model as we had known it.
From a personal standpoint, I am mildly conflicted. On one hand it is only $5, and it is optional. However, it does make a slight change to the f2p model, where before I could say "all content can be obtained within Spark without spending one cent", now it is adjusted to "virtually all content in Project Spark can be obtained without spending any money, with one content pack being the exception, and only being $5". The only downside to me will be that if I opt to not purchase this pack with Tokens, I will not be able to remix levels which include zombies.
However, one thing that I try to keep in mind is that this is a business. Microsoft will not let Team Dakota continue producing content for Project Spark if no money is being brought in. And this still cannot be called a "pay to win" system, how would you even define "winning" in Project Spark? If anything, it would be in relation to being able to produce a great game, and with so many factors going into producing a great game, the inclusion or exclusion of a zombie character model seems fairly small.
So while I would not say this is a Project Spark Zombie Apocalypse, I do think it is interesting, and we shall see how things go from here.
The official release entry is here: http://projectsparkblog.tumblr.com/post/79274303713/zombie-outbreak-now-live-on-project-spark