It's about time we removed experience penalties for being overlevel in a wilderness. The game has power creeped enough that any wilderness is easy beyond redemption. If a 29 level character wants to clear out korthos wilderness, let him do it. The difference between 2000 xp and 20 xp at level 29 is irrelevant anyway. Of course, that means it shouldn't bother the player either and that's true but it affects you in a big psychological way when there's a 'penalty' on doing something.
If you are worried that a level 20 will powerlevel a level 7 by clearing the red fens for him... do you actually play this game?
PS This comes to me as I am going through sands and red fens in epic. There is too much heroic xp for me to clear them out in heroic so I end up not doing them at all, not even the quests. Also, there's people farming feathers but that's a non-issue as it's only 1500 and it will be done before you even notice.