The other day I was thinking about how much bigger Garp and Dragon looked when compared to Luffy, and then it dawned on me that he's probably not even done growing yet!!!
One Piece has been around for a long time now, but we've (semi) confirmed that only a few months has passed since the VERY beginning. Sure, a lot of progress has been made, but Luffy is still only 17, and He wants to be the Pirate King, which means he's gonna have to fight his way past guys that have been at sea for twice his age.
So is the manga going to progress at the same rate it has been for the last 10 years and have Luffy become the Pirate king at age 18 (or 19, 20, etc), OR could it have a time skip so that the crew is more mature by the time the ending is actually in sight? I'm not talking about anything over 10 years though; that might be a bit too much. I just can't see silly little Luffy, whose not even done growing, become the almighty Pirate King.
I'm one of those guys that don't think the manga will end when Luffy gets to the end of the Grandline, since guys like Shanks and Whitebeard has probably been sailing around that area for the last decade, and for some reason they aren't crowned with the title of Pirate King (whatever the hell that means). It seems stupid that anyone who finds the one piece would automatically become recognized as THE PK. I think you also need to have sailed the entire world, and had adventures everywhere, as well as made a name for yourself in the GL. So I think b4 the manga ends the crew needs to leave the GL to further explore the seas.
I don't think the rest of the story would be spent exclusively in the GL, and I don't think Oda would have the crew find Raftel on their first trip to the GL. They could have their fun in the GL, and then do what Shanks did - sail the world for a bit and return to the GL after some time. It isn't necessary for Oda to show ALL of their adventures outside of the GL, maybe a few (esp. if they gain crew members in those side trips) because we can assume that all the big players in the OP world resides in the GL, and the story WILL end on Raftel or something like that.
There. That's all for now. What do you think?