User blog comment:Damac1214/Vonderhaar tweets interesting tweet about the possible future of Zombies/@comment-3967954-20130530120344/@comment-1055346-20130530232518

Also, @Aug: I can see this being true maybe for the more hardcore Zombie player, but for the casual players I don't really think so. I mean, what were the really major additions to MotD that really change the way Zombies plays?

1. Afterlife Mode

2. An Easter Egg that ends the game

That's pretty much it, everything else is pretty standard zombies fare. Some new weapons, new enemies, new puzzles, and a new perk.