Sorry, but no. Madonna is dire. In fact she's worse than that.

But I see no reason why Pacino cannot be in it. He died at the end of the third, but the time scale enables him to be in it. He could work with Garcia as a type of consigliere, and you could have him pondering where his fathers empire turned into his monstrosity where he alienated everyone- cue flashbacks about a young sonny, the ageing vito (de niro) and the wars with the irish, or running molasses during prohibition. How vito met luca Brasi etc,how he killed maranzallo (?)and sent Capone packing (stuff from the book). If done correctly this could be pulled off. For credibility i'd like shire, Pacino, De niro, garcia to act, and Coppola to direct.

Oh and the emphasis placed on flashbacks is due to the fact Garcia could not handle the movie on his own. An the film could not be carried solely on the premise of his empire. Perhaps for this angle, we could see the downfall of the corleone empire through vincent becoming involved in narcotics (he's sonnys boy after all)