Fashion trends change all of the time. Something that I have noticed is that many fashions often tend to come back into style in one way or another after a couple of decades.
Culture has definitely changed since in the 1960's. In particular, the roles of women have changed and "masculine" dress has become more acceptable. Clothes are not as gender specific as they once were. In other words, women wearing pants or suits instead of dresses and skirts is perfectly fine and culturally accepted.
It is inevitable that fashion will continue to change as the years progress.
To me, the single biggest change in fashion since 1960 has been the acceptance of women wearning pants. I think that this has been due to cultural changes.
My mother started college at the University of Idaho in 1961. This is, obviously, a state school and not a religious school. Even so, women were not allowed to wear pants on campus. They had to wear dresses or skirts. Nowadays, this haas clearly changed to a tremendous extent. Nowadays, pants are completely acceptable and pants that would have been scandalous in the old days are normal.
I think this has come about because of the change in the status of women. They are seen as more equal to men today and therefore able to wear "men's" clothes. Somewhat paradoxically, they are also allowed to dress in more revealing ways. This also has helped move us towards women wearing pants.
I think much of fashion in America after the 1960s has been reflective of its social and political context. For example, America in the 1980s was a period of time where women were entering the workplace as well as reflective of extreme wealth and opulence. This is why shows like "Dynasty" held such a major hold over fashion, as evening jackets and "smoking attire" became fashionable. Such wealth was reflective in the fact that "extra fitting" was critical in fashion. Overdressing and appearing well endowed with fashion was the fashion. "Power Dressing" referred to wearing clothes that reflected being a professional that was important. It also referred to how women dressed for work. It was complete with dress coat, blouse, and the shoulder pads that made women look more like linebackers, but was intended to convey a sense of "power." Costume jewelry was very big at the time, too. Before "bling" was "bling," the 1980s demanded that one become "blinged" to reflect wealth and status. This was seen in the very rich echelons of social settings, as well as in the emergence of rap music, where the thicker the chain worn reflected greater status of wealth and privilege.