What will the expansion do for end-game

So here's my generic question for Camate and Friends(TM):

Is the majority of SoA's game-play going to comprise of zone-wide player involvement (similar to Beseiged/Campaign), Alliance-sized (Similar to Dynamis at first release), or Party/Solo-scale events (such as modern day Dynamis and Abyssea)?

Additionally, and probably more to the point: In comparison to the Voidwatch "grind" that has become the primary end-game focus, how will SoA's content be pushed to players? Is this mostly for adventure/story? For the "ooh shinies!"... or basically, what is the intended goal for SoA?

They have said more will be announced later. From the looks of the exspansion video it still looked pretty earlier in development.