User blog comment:Kaido King of the Beasts/Chapter 769: The Good, the Bad, and the Bellamy/@comment-24769684-20141204232734/@comment-1595565-20141208053703

Considering his pace is slightly ahead that of the magazine, we won't find out until close to the end of the month or early January. Though I must say I'm intrigued. Based on current events I'd guess it has to do with auto-limb reattachment. Though the smart money is on it being about something deeper than that. My guess/hope is that it's related to Doflamingo's impending breakdown. Although for all we know the research could have nothing to do with this arc.