It was around chapter 600 or 601 when Usopp and Nami reunited and she basically asked him to upgrade her weapons. Around chapter 700 we get a quick panel of Usopp hammering away at something completely unknown and finally chapter 822 we see what it is! The magic wand Usopp talks about will be Nami's trump card in the stickiest of situations.
Reverie! Yabadabadoo!!!! I've been saying for years now that were given way too much foreshadowing for the next reverie to be happening after the crew finds One Piece. After Kaidou gets taken out would be the perfect time for that arc. The revolutionaries will most likely be weakened, an Emperor will be completely out of the equation, 3 of the current 7 War Lords will have been taken care of probably making it easy for Fuji to plead his case and we'll begin to see what could come of Queen Otohime's request to migrate her people!
With Jinbe fully joined by then, the Straw Hats crashing the meeting of the kings will give us a perfect opportunity to revisit guys like Stephy(was that the little punks name? Sabo's adopted brother?), who the king is in Goa kingdom, why the Celestial Dragon was there and specifically for Jinbe, Tiger's fleshed out Mariejois flash back! So exciting!!!!
I've had a feeling for a very very long time now that during the crew's meeting with Vivi this is when Robin will receive her 6th member chapter. For someone so near and dear to most of the crew I bet Robin harbors some guilt about her involvement with the near down fall of Alabasta. Once Robin gives her apology, expect her to start face faulting at least once every arc.