Rumors are that Pacino and Pesci could be looking to join The Irishman, a crime thriller based on the life of mob hitman Frank "The Irishman" Sheeran. Scorsese and De Niro have been developing the film for some time. It's based on the book, I Heard You Paint Houses by Charles Brandt.
Sheeran has made claims to be the murderer of corrupt union leader, Jimmy Hoffa, as well as having inside knowledge of the assassination of President John F. Kennedy.
If this film ever gets off the ground, it's not likely to be any time soon. Scorsese is currently shooting Hugo Cabret, his first 3-D film. Once that is completed he'll possibly direct Silence next, based on the novel by Japanese author Shusaku Endo.