You know, if pve players want a reward system, the only way I can think of one that would do the player and the game any justice is a kind of 'community leader' or 'guide' (for lack of a better description) reward. i.e. a bronze border around your guild cape or a unique shiney graphic you could put in some inconspicous corner of your cape.
Basically for people that are generally well known in the Guild Wars community for being helpful, friendly and generally all round smashing chaps. For sharing their builds, helping lowbies through missions alot and drok running people for free etc etc.
People could possibly submit names via forums like this and the coolest pve dawgs get a community pat on the back. Or a selective process by anet devs or something. Anet enables their trim capes. Or their different coloured name. Or their emote. Or whatever - the actual reward is very much open to discussion.
But I would consider this an awesome way of recognising someone's contribution to the game. Not only is it something to shoot for and a unique look but its actually some kind of incentive not to be a fricking a**hole. And theres too many of those in the game at the moment as is.
F

and dont forget the farmer emotes.