In the full translation from the last Live Letter, YoshiP mentioned a couple of ominous things about what the current game servers can handle;

Quote Originally Posted by Yoshi-P
Additionally, the congestion in North Shroud is quite rough, so we're currently looking into whether we should implement a system that has been adopted by other MMORPGs for making multiple instances of the same open-world area. The preparations have already been made and we've implemented this into the Chinese version of the game, so we do have some operative results. We'll be testing things up until the last minute to be sure that the concept of multiple open-world instances is clear for players who aren't used to this kind of system.
Can we please not? Instanced open-world areas are really immersion-breaking and anti-social and feel like a kludge. Please just invest in better servers for the long-term health of the game. If you had invested in better servers already there wouldn't be 500 different threads raging about personal housing right now.

Quote Originally Posted by Yoshi-P
Of the ideas we have at the moment, we are trying to make the final decision as to which solution is the quickest and would allow for the most land, as well considering the amount of time and resources it will take. Of course there have been those who have suggested spending millions to enhance the servers, but this would be the last resort for our engineers. We're currently looking into exactly how much we can increase the amount of land with our current resources and we'll be doing this right up to the last minute. If it appears that all other avenues have been exhausted, then I'll make the call to beef up the servers. At the very least, we will be increasing land in patch 2.38 and you'll also be able to start purchasing private housing.