Four different Japanese sites have been getting 4.1 info. Here are some of the more interesting points from them:
- They are starting to focus in  doing something about (the core system of) glamours
They want to expand on inventory slots, and also have smartphone app features linked to the game.
Though on the subject of making items stack-able up to 999, they couldn’t make it for patch 4.1.
The possibility of adding more Aetherlytes in the future = None- Royal Menagerie Extreme confirmedÂ
- Pre Patch 4.1 will see a small scale updates (PVP Adjustments)Â
- More ways for you to utilize clan mark logs and GC currencies, like exchange for more things and so onÂ
- 4.1 will see friendlist registration on different servers, along with Tell feature usable cross server.
- Return to Ivalice will see a whooping load of spoilers
- They will also announce a new high difficulty mode, harder than Omega Delta Savage in Patch 4.1Â
- NGC Crafting Committee might create a whole load of original quests for the upcoming 14 hour broadcastÂ
More info here:Â https://www.reddit.com/r/ffxiv/comments/6wj9b1/patch_41_new_information_from_game_watch_famitsu/