And what's wrong with that? He'd make an excellent crew member. Besides, every new addition to the straw hats was after a big conflict so it's logical.
Jinbe has played such a huge role in the story so far that it would be dumb if he didn't join the crew. Granted Vivi also played a huge role in the crew at the time, but she is a princess. No bounty at all. Jinbe is a pirate, with an extreamly large bounty. There is no doubt in my mind that Jinbe will be the next additon to the crew.
im glad to hear SOMEONE saw this coming