Quelques info aifaite, je sais pas si ça a déja été dit:
There are different skills for underwater combat.
There will be a Collector's Edition, but there are not details yet.
Duels are currently not planned (which does not mean they won't be added later).
There is no "tank and spank" in Guild Wars 2, even in boss fights the players have to be mobile and actively avoid taking damage.
While there are NPCs that will point a player to the nearest event, there are also events that players will have to find on their own by exploring.
The day and night cycle is not fixed yet, it's not in real time, and some events depend on the current time (example given was an event in the human starter zone that only happens at night).
There are dynamic events in world PvP (but not in the 5v5 mode, there are different maps, but once you enter the map you should be able to know what is going to happen in that fight without random elements).
http://gw2.univers-virtuels.net/news/23034/Interviews-Martin-Kerstein-Partie-2.html
There will be a Collector's Edition, but there are not details yet.
