No no no, there has been no talk of an expansion yet. Talk about putting the cart before the chocobo!
But what I did notice was that in the description of the Hyur, it states that they came to Eorzea from 'neighboring continents.'
Now, perhaps I just wasn't paying that close attention, but I had thought that Eorzea was the entire world (like the Earth). It would appear though, that Eorzea is just a region that encompasses the continent Aldenard as well as some of the islands around it.
So, this implies that there are other continents out there that could be used for future expansions!
I mean, sure I'm getting really carried away here. But I'm just so excited about this game that I can't help speculate about every little thing!