DragonMaster2010
Don't Let the Fall of America be Your Fall
While I think that Dante should be the protagonist for DMC5, I think they should introduce some new characters that could take over as the main protagonists for later games. Otherwise I feel that the series hasn't anywhere else to go storywise since its always revolved around the Sparda family.
I think that's where Nero's place is. Devil May Cry is, and always will, about the family and will revolve around them since Sparda is the plot device that ties it all together.