Superpowers, despite the decomissioning of nuclear weapons, still have a lot of warheads, both sides try to spread their influence, thought the balance tipped a bit to the west, and the world is still bi-polar. A slowly changing trend but nonetheless present.
Sorry if this falls in to current events category, I assume it's historical paralels.
It depends on what the Cold War was really about, yes? If the struggle was about capitalism vs communism, the fall of the government in Dec 1991 would signify its end. If it was about the German question, then it ended in 1963 and everything afterward were minor issues of great power rivalry. If if was about the domination of polarity, then it ends when the collapse of the Warsaw Pact. In sum, it depends on what the Cold War was about. It is cited as the dissolution of the Soviet Union because it was no longer seen as a world competitor