XG-PON1 versus NG-PON2: Which one will win?

By 2010, XG-PON technology had been standardized, but now NG-PON2 is following closely behind. The question of how these two systems will compete, coexist, or cooperate will be considered. NG-PON2 can be seen as an augmented version of XG-PON1, with a large amount of component reuse. So, it's not win or lose, but an orderly succession.