1. Legendary Ring… One ring to rule them all.. forging 3 rings into one + something else hard to get?
2. Allowing user contributed content into the game. For all the nerdy guys out there, me included, who like to play this game, but also have graphic and programming skills. Maybe allow users to create new skins. Maybe even new levels? Understandably you may not want the regular map area built upon by users, but rather you could implement another portal area similar to Fractals, and instead of a selecting fractal level 1 to 100, we could select user made levels. Of course all user made content would require approval by ArenaNet staff, to approve or deny each user submission, but the man-power required to do that could be minimal, and the cost of the new content would be made free by users.