The black beret began as a symbol of distinction awarded Ranger infantry. Rangers saw the green berets on Green Berets in the 1960s and did not want to be less special than the Special Forces. Shortly afterwards, airborne jump school cadre began wearing cranberry berets.
The beret impetus had another source; the army was wearing ugly, lopsided baseball hats imposed by Creighton Abrams near the end of the Vietnam War (IIRC).
One of the Clinton generals, later eased out by Donald Rumsfeld, had the brilliant idea of making every soldier both special and elite by giving the entire army authority to wear the black beret.
The Army Times reports that the beret has been scotched for a field cap for line troops. There is a practical aspect to this. As one soldier noted, "I hate wearing a wet sock on my head. Plus it makes my head/skin break out."
Now if we could just go back to making the wearing of fatigues off post or in the office a UCMJ punishable offense, this old soldier would be quite happy.