A new PvP format has been introduced to Guild Wars called Codex Arena. Basically it seems like Team Arena except you can only have one of each primary profession when you go in (e.g. no two Warriors allowed on the same team) and you have to pick builds from the limited number of skills provided from the "Codex". I personally think this is a welcome addition since it allows players to truly test what they know about the game (as opposed to those who just copy builds from elsewhere without having any idea of what they're actually doing!). Still, I have reservations on how popular the feature will be though!