I am betting the expansion will be the 19th Century, but I hope that they really do add the rest of the World in the game, even if some areas are left as just trade zone ports.

Imagine having different various systems within the game. You install a communist government and you have no upper class problems, but might suffer on tax income a little as there is no upper class to tax.

Anyway, just as a point how the game is atypical itself. Communist Manifesto came out even before America abolished slavery, yet, you can have the technology skill researched for that freedom in the 1700's.