I'm from SEA (South East Asia) and having 270-400 ping. While casual playing is fine, it's noticeable that many times there are lags and delays. Even as a tank it got difficult. I actually couldn't enjoy my NB or Mage toons with this connection.
I read around and it seems like a lot of people from Australia and Japan are having the same problem. Again, while the game can be played, it gets annoying because there are times that timing is crucial. (Block/Shield/Heal/...) 200+ ping can screw things up. Last night I actually had 500 pings at all time, and the only thing I could do was mining and picking flowers.
I know this is not a normal question, but if you could put a server in Singapore or Japan or Australia, and link it with the NA Megaserver, it'd be great. Making a separate Asia sounds too much of a trouble for a 2-3 years old huge MMORPG I would think.