It's break week, so there isn't anything new to discuss, at least for the manga proper (there are some new Vivre Cards dropping).
A lot of current speculation and theory crafting is fixated on Egghead and the Void Century right now, but are there any mysteries in the series still lingering that you hope will be solved at some point? Or even concepts/locations/people mentioned that have not been shown?
Personally, I'm interested in the purpose of Lodestar Island. It shouldn't just be a plot device used to introduce the Road Poneglyphs. The bit about Crocus lying can be waved away as a retcon, but will we ever see the island? What causes it to have such odd magnetism? Is there anything on the island that informs travelers about the Poneglyphs?
Post any other mysteries you're fond of below.