In guild Wars 2, the worlds share the instance with other worlds that are in the same region. In Wow, most of the realms are connected together. There are some that are not connected but most of them are connected together. when that happens, its 2-5 realms that are connected together. When they do that its the character name-server name. That is how you also mail items to your characters if they are on connected realms.

I honestly think that we should go either route. Either go with all NA sharing the instances with other NA servers and EU Sharing instance with EU servers. If we go the route that WOW has this is what I think the connected servers should look like.

North America

• The Shadowlands and Jedi Covenant
  
• Jung Ma, The Ebon Hawk, and Prophecy of the Five
  
• The Harbinger
  
• The Bastion and Begeren Colony
  

Europe

• Tomb of Freedon Nadd, The Progenitor and The Red Eclipse
  
• Darth Nihilus, Battle Meditation, Mantle of the Force
  
• T3-M4, Jar'Kai Sword, Vanjervalis Chain
  

I kept Harbinger by itself because I felt it was big enough without adding another server to be connected with them. If this could be put in, people would not loose their current character name. All characters on connected server would have either character name@server name or Character Name-Server Name. I also know there are people who like to be on low pop servers and in order to cover that, there will be an option in your settings to choose between low, medium and high capacity instances.

When it comes to Legacy, each connecting server would be separate. I honestly think its time to make Achievements and reputation accountwide and maybe add an account bank. We will still have Legacy banks. Guilds would be across connected servers so if there is more than one guild with the same name, they will either get guild name@Server Name or Guild Name-Server Name