This apparently will replace All Things Zombie: Better Dead Than Zed, which is the core rulebook of the system.
I don't know how I feel about this. On the one hand, something a bit easier to understand would be great. Some of the layout of ATZ:BDTZ could stand reorganization! But there have been comments about increased complexity....which I don't like. I'm a simple rules sort of guy, which is why I'm a host on the Classic D&D podcast "Save or Die!" (http://saveordie.info). I like basic rules and options, like in the third book of the trilogy I, Zombie. But new rules? More complex rules? I dunno...
Vampifan (see my blog list for his blog) is one of the playtesters and I've got a lot of respect for him so I'll give it a chance when the book comes out. Still, I just got my 3 books (BDTZ, Haven, IZ) combined into one big book! <grump>