The Encounters system is nothing new. Other then the title itself. Those of us who remember the knights in the chaos sanc paid a heavy price not learning how to prioritize attack methods, as well as which direction to attack in a Uber Tristram instance.
i think the point is there are going to be more monster types with more specializations and abilities other than curses etc. which will force you to change your play style and use different abilities to take them down. other than that i'm not really sure what your question was before.