Virtual line in Mexico, or for that matter any of the rides in the World Pavilion would actually work really well. If they limited you to the bounds of the country, you would be forced to shop and take in the other sites. Learn more about the country, do the Epcot festival thing for that country... it would actually be really cool and fit perfectly with Epcot's original education vision.
How many people have actually been in the Hedge Maze or back alleys of UK (I know no ride yet), go through the Norway (Frozen
) history building, really explore all the shops in Mexico?