Director Stanley Kubrick died in 1999, but he left behind an unfinished screenplay about the life of Napoleon Bonaparte. He started work on it in 1968, shortly after he finished 2001: A Space Odyssey. Kubrick said it would be "the best movie ever made" and wrote to Audrey Hepburn to get her to come out of retirement to play Napoleon's wife Josephine.
He wrote a draft in 1969 (read it here) before bringing on Anthony Burgess (A Clockwork Orange) to write a novel upon which he could base the film. Kubrick rejected the first half of Burgess' book in 1972, but Burgess finished the book anyway. The project was dropped by the late 70s, but not before Kubrick amassed a huge amount of research.
Steven Spielberg told a French TV station that he'll be adapting the script for a television miniseries. They worked together before Kubrick's death on AI: Articificial Intelligence, which Spielberg directed, but Kubrick had developed in the 70s—so perhaps he can do it again.