So it looks like each race is split into two parts. The Roegadyn come from the north and mostly live by the sea and value strength and courage, except for those who live in the mountains and practice magic. The Miqo'te are separated into Seekers of the Sun and Keepers of the Moon. Most of the Elezen have made peace with the Hyur, except for the Duskwight Elezen. The Hyur themselves are divided between the Highlanders and Midlanders.
There's been a lot of speculation that these distinctions will take the form of different playable option. For example, you could choose to be a Seeker of the Sun or a Keeper of the Moon. But what if this isn't the case? What if the other half of each race (Keepers of the Moon, Duskwight, etc) are the "Beastmen" of FF XIV? The sentient enemies that we'll spend much of our time fighting?
Just some idle speculation.