@ponx:
I still don't think it'll take another arc or two to finish his duty. After all, one of the most common thing among the SH is that Luffy has helped them deal with their personal issue/baggage/etc. Directly or indirectly, one way or another. It won't be different this time, plus it'd be weird that during Luffy's toughest moments (ID & Marineford) Jimbe was there to help n support him. But Luffy isn't going to do the same thing for Jimbe.
I agree with this. Luffy obviously respects jinbe a lot, there's no reason he wouldn't help out.
Also, I think a lot of the negativity surrounding shirahoshi joining is the sheer lunacy behind it. I will say that in her defense this is one piece and it's highly unpredictable, this is a series where MUCH weirder things happen on a pretty much regular basis. Yet, every time someone said shirahoshi would join i had to wonder if they were being serious or just expertly trolling. It doesn't seem like she has any desire to go adventuring or become a pirate, her size and ridiculously low strength (outside her ability to call sea kings) is another issue, and the fact that there doesn't seem to be any good reason why luffy would even want her to come along, are only some of the examples why a lot of one piece fans think it's a ludicrous idea.
Even if Shirahoshi is captured, which i think is pretty likely, you guys have to remember that it's not like people can just abuse her powers. SHE'S the one who calls sea kings, even if her captor beats her within an inch of a life she doesn't have to call them, and furthermore she can't even control this ability (yet). If they come due to her unconsciously calling out to them, why would her captor be able to use her to control them against her or their will? As I said before, even if she is a threat to fishman island, even if people would come after her, why should the straw hats have to shoulder the burden of protecting her and keeping her safe? Isn't that what her brothers are for?
One last thing, since this post has basically nothing to do with the chapter (i am truly sorry about this, i know how juvenile this post may seem to some), people have been coming to fishman island for years now. And not just low level pirates. We have to assume that since all the supernovas are in the new world as of 2 years ago (with the exception of law), they all had to cross fishman island at some point since that's the only way for pirates to realistically get to the new world. Yet, despite fishman island's sheer amount of tourists and pirates coming through, no one outside of the fishmen themselves and robin have been able to gauge that shirahoshi actually has this ability. Hell, the only reason VDD knows she can call them is cause of the family legacy. So, why does everyone think that suddenly every villain in the one piece world is going to be gunning for shirahoshi to take command of her powers? This, alongside the theories that she will join, just seem so self defeating. It's like they debunk themselves.
I do think Shirahoshi will be kidnapped, probably by Caribou, but for the simple reason of her being gigantic and a mermaid, and obviously due to these qualities would probably fetch an outrageous sum at the human auction house. EDIT: due to her status as poseidon, i'll admit that shirahoshi is probably going to play some large role in the future of the story, probably something involving noah. But for her to join the crew? I understand that i am not the god of one piece who dictates how the story will go, and it's not like my opinions matter more than any one else's here, but this idea just seems ridiculous and i think a lot of people would agree that–for a plethora of reasons--it is.