To be honest, I don't care about the multiplayer problems at all.
What makes the first game so special to me was that it was one of the very rare games in that survival zombie direction that completely focused on a single player experience. An open world, survival elements, crafting, building, expanding bases, people you can loose forever and everything as single player, that was amazing and if the second game is just better and bigger in every part (and hopefully still has the focus on the single player), that's enough for me.
I only watched the very first IGN gameplay video so far and the coop in it looked horrible and destroyed the immersion on every little corner. It just looked arcady and they were doing the same stuff all over again. If that's what people want, fine, but I stay in the atmospheric immersive single player campaign.