The solution to congestion in certain areas.

[Betelgeuzah]

I think this is a good trend for testing purposes. The Thanalan region essentially represents the game servers as a whole when the PS3 version is released (in theory), so they can gather data as to what bottlenecks there might be and get rid of them.

So I think they should keep the area congested and figure out alternative solutions to the problems. When the servers are full, dividing the playerbase across all zones won't be an option anymore.