I know GW:EN will come out soon enough, but it wont hurt to look toward the future.
What do you want in GW2 that isnt known to be included already?
For me, i would love to see little things. Just minor things that you can work towards perfecting your character. (Of course not giving anybody a large advantage) Sort-of like crafting, fishing, hunting. These minor attributes could be fun to work towards, but not a large part of the game.
Edit: Spelling
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