Could be a nice new page on your avatar screen...
There you'd find each achievements name and date time.
Like 6000 kills, keepers'butcherer:1000 kills, potion-ogre: 20000health potions bought, death-lover: 3000 etc
That'd be some easy new quests/objectives for lvl50.
Getting sometimes freebies out of some would be nice too.
Sounds wow-ish sure but the *one I'd really like to see sometime would be the [ lvl1-50 : 3 days - "speeding ticket" ]

Granted if you guys didn't store this kind of data so far, only beginners will end up having achievements... So forget about it
But still. I wish we couldn't be allowed to hide some stats or wish we had some new ones (very expensive to hide) that'll show our dedication as a player.
Created in / level30 reached in... Hours / level1-50 in ... Days etc.

Power leveling isn't be any means something that help your customers get addicted to your game.
But ok... Nothing new here I guess.
Thank you for this neat game and your efforts