What will one piece be? Is it the Rio Poneglyph? Is it a Mountain of treasure? Was it Ace? Is it the Straw Hat? A note that says " I owe you one treasure " ? Whitebeard confirmed it real, so it cant be something metaphorical, like One Piece was inside you all along or One Piece is the power that brought you here.
Also was Roger like Luffy, back when he had the Straw Hat? All like " OH Rayleigh, YOU KILLED HIM IN ONE SHOT, SUGOI !! " all starie eyed?