Wouldn't it be cool and fun to have a dungeon where you only may enter if you havent got any items on paperdoll nor in backpack? You'd have to drop all stuff at bank/home and find usefull stuff on monsters or floor, maybe even buy some gear inside from npcs or other players. You would be able to bring stuff out of there of course, but not inside. I think this might be fun and challanging. Stygian Abyss would be perfect to introduce something like that, thinking about Ultima Underworld where you got thrown into it as a prisoner.