I already read something about duells and that the game designers don’t like to implement duells because they say it destroyes the group-based pvp-system.
In my opinion Arenanet tries to hard to protect the players among themselves in pvp. For example there are no emoticons that can provoke somebody, or the fact that in WvW no names of the opposing servers are shown.
I totally agree with you guys that duells have to be implemented because as you already mentioned they are one of the two things that kept me playing; arena matches and duells.