Wouldn't it be well cool tho if they did add bosses to zombies on Map Pack 3 and then they did a trailer.
The trailer would be like you killing Zombies then you hear this laughing then you hear loud footsteps then like you said a zombie boss breaking through the wall.
Then 4 people Spraying it with light machine guns and the Zombie Boss Walking Towards you.
That would be an awsome trailer LoL