–Luffy keeping the Mera Mera no Mi stashed away somewhere safe on the Thousand Sunny.
--A GREAT amount of time will pass (like Luffy will become the Pirate King, and defeat Fleet Admiral Akainu time pass).
--During the final scenes of the series, a kid who looks up to Luffy will "accidentally" eat the Mera Mera no Mi, and Luffy and crew will have the same reaction Shanks and crew had when Luffy ate the Gomu Gomu no Mi.
--This will be a passing of the torch, of sorts. To the next generation. (Heck... Maybe the Gomu Gomu no Mi belonged to the brother/step-brother of Gol D. Roger, and he kept it safe after his brother/step-brother died early similar to Ace). (Maybe, just maybe, if the Strawhat's acquire a Cabin Boy, he will be there instead of Luffy (if Luffy dies) when the kid eats it).