"If they make another, it should be like GF2 where you have Sonny and Tom Hagen in their youth, and then Vincent Corleone overseeing the final days of the Corleone empire."

It's like you read my mind :o! I think that this is strictly a way for Paramount to make more money. They don't care what we think, they only care about the money. If they were gonna make a Godfather Part IV involving Vincent they would have done it by the 1993-2001 range. Waiting 16 years to make a sequel {like GFIII} is a little to long for me.