In a press meeting Yoshi-p was asked how long this "new" story will continue and he says at least two expansions, but probably more if the players like it.

Which then leads me too "The Golden City". I'm sure everyone is familiar with the legend, but casting anything as "golden" has become a metaphor for something so amazing and advanced you can begin to comprehend. The common allusion for this is the streets in heaven built in gold. But heaven can't literally be built in gold so it is something beyond understanding. So, setup for this journey seems fun, but really when we get there, what will we find and what will it reveal? Whatever it is will spring board us to 8.0 and beyond.

Furthermore, if you slow the trailer at the end when you see the WOL standing at the helm, you can clearly see a person whose face is obscured by a sail wearing the blue and white outfit associated with Alphinaud and piloting the ship is a darkened (probably on purpose) Lalafell, who is probably Krile. So if we are using this as evidence, the faction the WOL sides with will be Krile, Alphinaud and Erenville as they are the people the WOL is traveling to Tural with in trailer. The keynote goes on to claim that a visitor from the new world will be the one to bring the WOL to Tural, so we can assume this new mysterious person will be the 4th rounding out the party.

Also the WOL is fighting Gulool Ja Ja in the trailer and this doesn't match what was said in the keynote (that Gulool Ja Ja is looking for successor). So some sort of political turmoil will see us on the wrong side established rule and if we take it a step further, the mysterious character who hasn't been revealed to bring the WOL to Tural will most likely be caught up in this struggle as well.