Ok these are 2 predictions I think got a good chance of happening in the next couple of chapters.
A) I think Mihawk will tag along with Zoro back to the sunny (Not as a possible crewmate)just to head to the new world for his own reason, I don't know meet up with shanks or w/e the reason. Why? Because Mihawk is Zoro's goal if he stays on the island Zoro will leave him behind mid-way through grand line, I think Mihawk will travel to the near end of the grand line parting ways with the straw hats obviously off fishmen island or sooner.
B) Pretty sure there will be a fishmen island arc, Luffy will run into some kind of situation there. Why because Whitebeard is dead so all of his islands that he protected are in danger, we already saw Bronzebeard's example. So I think Luffy will be claiming WB's old islands by painting his crappy version of his crew symbol over's WB's. Think that might be a gag Oda will do with him