Jota 180, the functionality of the existing phone remains the same when a new model is released (obviously) but if the new model has a better screen, larger battery etc it will be seen as an improvement, this hits second hand values of the previous model.
iPhone 4S prices dropped when the 5 was released….the same will happen to the 5 if Apple release a 5S next year….and eventually Apple stop rolling out iOS updates to older models.
Can’t believe I had to explain that, it’s not a difficult concept and happens every day in other industries….a new model of a mountain bike for example hits the second hand value of the one currently out there..doesn’t change how the bike works, just takes the shine of it and reduces its monetary value.