I actually have always loved this idea. i certainly think that Talia and Andy (two Academy Award nominees) could pull it off. They need that connection to the original family that Connie would bring, because like it or not, Vincent just wouldnt be the same considering he wasnt involved in the first two. i see it like this, connie is in her 70's, but unlike michael she has not mellowed and has ordered the hit on numerous people. she is brought up on charges with the federal court, when kay has ultimately had enough. she and Anthony try to overthrow connie and vincent, in order to secure Anthony's rightful inheritence. what follows is the ordered death of kay's loved ones (a nosy sister or something), and anthony's killing of vincent. a final showdown in court of connie, with kay brought in as the key witness, and thus the end of connie, vincent, and the corleones. they are legitimate with Anthony, and Kay has finally brought down the family.