More information on the game expansion will be shared during the London and Tokyo events, scheduled for October 25 and December 20 – 21, respectively.

But here is a summarized rundown of the revealed information

Ishgard will finally be implemented.
Focus on Dragoons vs Dragons.
Knights of the round hinted as well
Designed to have a much darker & mature look.

Increased level cap of all classes to 60.

New areas to be introduced.
Apparently very large compared to current size.
One new area is called The Dravanian Forelands.
Chocobo Forests are in.

Brand New Race!
It is NOT Viangaa.
It will have both a male and female gender to choose from.

All new Jobs will be included.
More information at the London fanfest.
Of them is hinted to be similar to The Dark Knight, Batman.

New Primals.
Brand new ones to the series will be introduced.
Special Odin battle for fanfest. It is not exclusive to fanfest though.

New Dungeons + High-End Raids.

Airships Galore.
FC can build airships.
Floating continents in the sky can be visited. I wonder how?

New Gear and Recipes.

New Beastmen dailies.