The fall of CoD

We all know that all good things must come to an end, and the CoD series will be no different. Some time in the future, IW and Treyarch are going to run out of ideas, and the CoD series will die. The question is... when? When do you think the series is going to die, and how do you think it will end? Will it go out with a bang, or go quietly? What do you think? When, and how?