Got a mail with updates on Dead Frontier today. Thought I just as well could post it here.
"We've just released 20 new types of infected into the streets of Fairview. This pack of enemies is comprised of 13 special infected and 7 huge bosses! Unlike the previous set of infected, these new zombies have some mean special abilities and will take some real tactics to defeat.
In addition to this you can now loot the corpses of bosses and burning zombies. They only ever drop weapons and armor, so you have a high chance of scoring a valuable elite item."
So I guess the hard areas finally will be getting harder? Hope so, the experience rate get slower at higher level, and it takes time to build up aggro to attract bosses/specials.