Looking at the website I never really noticed all that empty space, besides the Outpost spot. Every other nook and cranny has something to keep your eyes busy that you can actually fit QUITE a few more pavillions, and Disney originally wanted to add 3 more right off the bat. Israel and Africa would have been blah, but I think they are mainly looking at adding Brazil because currently they have no South American countries in WS. And to keep this continent out is rather shocking. So they figure its a win-win to bring in Brazil and make money on the BTG's
But if they add Brazil, then at least 2 more of these choices should be added too: Spain, Greece, Russia, Austrailia, Switzerland