If there were to be a GIV.......?

I feel that if a fourth installment were in the works the only way it could truly be succesfull is to have DeNiro play the Don again. I love Michael Corleone and Al Pacino I think its some of his best work and one of the best characters ever. However being a huge Godfather fan the person I want to know more about is Don Vito Corleone and if there was a fourth movie I feel that it would have to focus mainly on him. Michael has run his course of attention in these movies and its time to return the focus being on the Don. Please let me know what you think of this.

The only problem is that DeNiro, while still being one of the best actors of all time, is now too old to play the part of Don Corleone, since Vito was a young man (as was DeNiro) when he played the part in GF II.

The image of an elderly Don Vito has been immortalized by the one and only Marlon Brando, and anything else does not do his performance justice.