
Well i shall start off with
Character Switching (Not having to login again would stop people having to reconnect to the game and also it will make things easier for us
New Map System (Let us change maps rather than using the travel system.. would save alot of bandwidth)
Alliance Battle on Map put a alliance battle outpost on the map so people dont have to go to the guild hall
Personal Town System (I know this takes away some of the Onlineness of a game) it will only connect you to a town map with your party or henchmen so no more WTS everywhere
Auto Updater able to be turned off...
Full Client Mirrored etc at the moment you let people download the installer for the login menu and people auto update the full game to them.. why cant people download Full clients im sure that websites will be happy to mirror them like File Planet etc
If you do this arenanet then there will be no excuse why a auction house cant be added since your bandwidth cost wont be bad at all
Please add to this list and /sign as much as you can if you like the ideas I personally want Arenanet to see this.