A GF IV? Why not?! Besides all the great themes and twists you Wise Guys have already covered, there are so many possibilities and previously unheard of conflicts the Corleones could face in the 21st Century: rich-but-punk gangbangers, foreign terrorists who inadvertently "muscle-in" on Corleone turf (who WOULDN'T wanna see the Corleone's vendetta against THAT type?!), powerful corporations butting in, etc. etc. etc. Besides, there's a whole new generation of great actors we could see strut their stuff!