Basically in GW2 gear comes naturally as you level and play the game. You won't have to grind dungeons to get that unique drop that will give you access to another dungeon where you will have to grind gear again. All gear is obtainable through various means, hell you can get PvE gear by participating in WvWvW. When you kill a player in a PvE setting, the player drops PvE gear, and again it's not some useless piece that you're gonna have to vendor, it's the same gear you'd have gotten by running a dungeon AND it will always be level appropriate : Let's say you're level 15 and doing WvW, you automatically get scaled to 80. Now let's say you kill a guy who is really level 80. He will drop level 15 gear
Another thing to keep in mind if you like organized PvP : you don't have to grind honor/conquest/whatever sets to be competitive, everyone doing a Warzone is
given the same gear. So no more "people in their PvE set ruining everything", only skill matters.