Lifetime of creator + 70 years in the US, or lesser of (95 years from publication/120 years from creation) It's quite absurd. They keep extending it at Disney's behest.
It wasn't just Disney; it was also Gershwin. But here's why I don't see it happening again before 2024, when the works establishing key Disney franchises (Mickey Mouse and Classic Pooh) are set to enter the public domain in the United States.
The rest of the world (Berne Convention signatories) adopted the life of the author's grandchildren as the rationale underlying the copyright term
over a century ago, on the basis that those heirs who knew the author personally would be in the best position to carry out the author's wishes. The term of 50 years after the death of the last surviving author was chosen as an approximation of this. The switch from up to 56 years to life plus 50 in 1978 was a step toward joining the Berne Convention, which the United States completed in the late 1980s. The extension of the term of copyright in existing and corporate works to 75 years after publication was also an approximation of a work being published 25 years before the author's death.
Over the course of the twentieth century, health care improved drastically, causing grandchildren to survive their grandparents much longer. This led to an extension to 70 years after the author's death, which took effect in Europe in 1993 and in the United States in 1998. When upholding the 1998 extension in Eldred v. Ashcroft
(2003), the Supreme Court bought the excuse of harmonization to another major industrialized English-speaking market (Ireland and Great Britain), but the opinion of the Court was careful to distinguish this harmonization from "legislative misbehavior" intended to circumvent the Constitutional "limited Times" restriction.
If large publishers of works are sitting on an excuse to change the copyright term rationale from the century-old life of grandchildren, they haven't said anything. The most recent trade treaty proposals, such as the Trans-Pacific Partnership, are still based on life plus 70.
ObNES: This affects which characters and what music may appear in games.