So basically, trophies. The trophies would have the achievement's name and be time stamped with the date, either on the trophy or in the trophies name (the one that floats above an items/player's head). You'd get them for doing particular achievements while they are still relevant (pre nerfs/pre "expansion came out so I'm now higher level and stronger though scaled down") or for doing an achievement under certain conditions, or just for particularly high end/difficult achievements. You'd put the trophy down at your feet where it is displayed to other players in the world (limited to one trophy out at a time to avoid spam) and perhaps do so by double clicking the achievement, similar to using an item.
They are relatively small, wouldn't take up notable development resources to make, aren't overtly special or individually desirable or grand, but as such are perfect as a limited time only type reward and would serve the simple purpose of being able to be display in the game world and say "I got it and I have something to show for it".
They could also be used to (showoff) decorate the player's house and guild halls when they come out
Edited by Arewn, 08 July 2012 - 08:42 AM.