Guild Wars 2 Team posted on the official GW2 subreddit a post detailing all the remaining issues that are being worked on. In the meantime there was a patch deployed that might have already improved some of the things mentioned. Here’s the status of the most important issues being tracked:
  

Account security – We’re seeing an uptick in reports of account theft and attempted account theft. We believe hackers are using databases of email addresses and passwords stolen from other games and web sites, and pre-existing trojan horses, to search for matching Guild Wars 2 accounts which they attempt to compromise. To prevent this, we have temporarily disabled the “reset password” feature, and we’re working to bring email authentication online. To protect yourself, please ensure that you use a unique password for Guild Wars 2 that you don’t use for any other game, email account, forum or web account.
  
Email authentication – Email authentication is a feature that notifies you if someone tries to log into your account from a location you’ve never logged in from before. Thus, even if someone guesses your game password, he can’t log in unless he also guesses your email account password. You can make email authentication even more secure by using an email provider that supports two-factor authentication, such as Google or Yahoo, and taking advantage of that. We’re currently preparing email authentication and intend to deploy it in a phased rollout, starting on Thursday, August 30.
  
Parties, guilds, etc. – Parties, guilds, and other social features are periodically failing. This causes issues such as party members not appearing on the map, and party members not staying in the same overflow servers as they travel between maps. This happens particularly during times of peak usage. We’re working to fix related problems and mitigate this issue with each subsequent update.
  
Worlds – Many worlds are filling up. We’re keeping the number of worlds constrained so that worlds stay well populated even after the initial surge of high concurrency. However, we will add worlds as necessary. As of Wednesday, August 30, all German language worlds are full and all French language worlds are at high usage, so we’re adding two new German language worlds and one new French language world.
  
Overflow worlds – During this initial surge of high concurrency, and especially while many characters are low-level and thus playing in the same starting areas, it’s common for players to be directed to overflow maps. If you want to play with a friend, but you’re not on the same overflow map, you can form a party together, then right-click on your friend’s portrait in the party list and click “join”. Note that this functionality is sometimes intermittently unavailable due to the “parties, guilds, etc.” issues noted above.
  
Trading Post – We’re working to bring the Trading Post back online. To help test, we’ve temporarily made it available to a random 15% of players, while we work to resolve remaining capacity constraints that will allow us to open it to everyone.
Edit: We have completed our live testing of the Trading Post for today and the Trading Post is now in maintenance for all players. Thank you everyone that participated; this test has helped us tremendously.
  
In-game mail – We detected a potential abuse of the in-game mail system and have temporarily disabled in-game mail to prevent any such abuse. We’ll reenable it soon, hopefully in tonight’s update.
Edit: The fact that in-game mail is disabled means that it’s currently impossible for account hackers to loot stolen accounts, so we’re going to leave it disabled for just a little while longer, while we work to ramp up email authentication.
  
Botting – We’ll start substantial banning of bots on Wednesday, August 29. Since we’re currently seeing widespread casual, unsophisticated botting, we will start with 72-hour bans for first offenses. In the coming days, as we address the casual botting problem, we plan to switch to our normal policy of permanently banning anyone who runs a bot.
  
Forums – Our most important priority at the moment is to ensure that the game runs stably and flawlessly. So as to not create additional demand on our infrastructure and on our programming team, we made the decision not to open the forums until the initial mass influx of players has calmed down a bit.
  
Next software updates – The next update of the game server and back-end server software will take place tonight at midnight Seattle time. The game may be unavailable for approximately 20-60 minutes while we perform the update. We expect this update to have fixes for email authentication and in-game mail. Our continued work on the Trading Post is not tied to game updates, so we will continue to test Trading Post updates throughout the day.