I am looking at it from Google Earth and I guess I"m just not seeing what most folks are. I have to agree with the OP - no way is there room for 7 more countries.
Remember that there is a theming for each country and the vegetation that separates them is there for a reason - it's a buffer zone so that you are not in Japan one second and then in the middle of Morocco at the next step. I think that buffer is very important to the Imagineers and their plan for World Showcase.
There is room for a new country at the African Coolpost area, but there is certainly no room in that area or behind it for a similarly-size lagoon with 7 countries around it. There's enough land for one country and then a small waterway and then a road (Buena Vista Dr) and then the CBR on the other side of the road.
Even if you wanted to wedge them in, let's take between Mexico and Norway for example, it's not easy. Looking at the space in Google Earth there's a wide area of vegetation, yes, but there are lots of storage/backstage buildings. Look at the Mexico building or the Norway building - a building that size would fit in that space between the two pavilions, but it would be a tight squeeze and it would wipe out all those backstage buildings.
I'd love new countries, but not at the expense of the theming of the existing ones. I don't want them shoe-horning in things right on top of each other.
