This, from what I'm told, was shown at a JP (go figure... they never tell us anything directly) gaming expo. This would be the completely world of Vana'diel. Of note to some people, the Island of Tsahya is the home land of the Mithra. Also, the other continents are often mentioned in passing in various places in the game.
Something notable is that there are dots on the map that one would assume represent cities (big ones with MHs). There 15 of these in the unreleased areas. Pretty incredibly considering we've only seen 5.
This seems pretty ambitious for SE, though I have doubts that all of it will see the light of day. Considering it took them 4 years to give us just half of the Aht Urghan Empire, it seems it would take them another 15 years at their current rate to release it all.
I still think it's really cool and while I think they should work on fixing the current problems in the game before getting too crazy with extra content, it really does make you think about how much could potentially be in store for the game if they are able to maintain enough playerbase to make it worth funding the expansion of Vana'diel to its completeness.
It seems to me that for them to go really make the progression that so much land would require, they will almost definitely have to raise the level cap (which they said long ago they won't) or at least start dramatically improving gear progression.