What about other nations? It was stated by the devs themselves that we're going farther north in the next installment. The countries lying to the north of Orlais & Ferelden are Nevarra, Anderfels, Rivain, Tevinter, and the Free Marches, though technically it is not a country.
Nevarra - There's a lot of nobles there and most of them are Penthagasts or other houses related to the Penthagasts. Every origin story could be possible here, from human noble through dalish elf to tal-vasoth qunari.
Anderfels - This would make a great place for the human commoner origin, as most of the people here are farmers, soldiers and Grey Wardens, so mostly common folk. The King is weak, nobility is probably small and Wardens Hold most of the political power.
Rivain - Here's the only qunari settlement on mainland Thedas, so a qunari origin could start here. Actually, any origin could center around the growing qunari influence in the land, which forces the main character away from his/her home (we probably never going to play as a faithful qunari).
Tevinter - As discussed above, human and dwarf origins could work well, but we don't know enough about elves and qunari in Tevinter and how their origin story would work here.
Free Marches - Again, a largely neutal land, where all origins would work, regardless of race and class. (Personally, I'd love to see the other Free Marches cities visited in one game - urban areas can be much more interesting, if done properly with no re-used areas).