Here a list of some ideas, most of them I used in MMORPG where I worked and seems nice:
- readable books (and also writeable if blank)
- magic book that teach some skill
- magical items: rings, earrings, bracelets and all the other D&D like magic items

- cursed items
- housing (sellable houses)
- slottable items (items that can be enanched with magical or special features using certain skills
- magical eye, magical ear objects. Small objects used to spy other guilds, enemies.
- unique items (artifacts)
- famous places, or special places, like: the \"dead dragon tavern\", or the \"mountain of the evil necromancer\" or something like that...
- automatic quests (some of them level limited: for newbies, average, experts and so on).
- special NPCs, uniques. With special characteristics and that speak sometimes. Used for some quest and/or to be a \"noticeable\" thing.
- a werewolf like monster
- a doppleganger like monster (that take the shape of one of his attackers/enemies)
- a displacer enemy (that teleports hitself nearby sometimes during fight
- recipes book and recipes
- ability to look for herbs and other components around the world
- butterly and other animated \"background\" elements to make the world more \"live\"
- secret passages (some with magical \"words\")
- guild/clan channels (with /list command to see teammates online)
- online players list (on website)
- guild/clan buildings
- players\'NPC merchants
- armor&weapon sets. If you find all pieces you get more \"power\" than the sum of the single objects powers of the \"set\"
- living trees (treants)
- swimming (a dream

)
- the feature of \"grouping\" with a /group command or, better, mouse command. Each formed group has a \"personal\" channel that can be used to speak and a command to see the members of the group. Groups are temporary (they can be removed if each member is not online or if the group leader erase the group. There\'s a command to see all groups, with leader.
- use macros and \"direct write\" instead of the \"click-write-click\" method used now. Is REALLY MUCH MORE friendly and nice for a MMORPG.
- avoid the /command only feature and prefer click/macro based interface (with also function keys and ALT/CTRL+key to call functionalities)
- tent and camp fires
- cannons, balista, catapults, caravans...

- ships? galleons! ^_^
- treasure maps randomly generated...
- explosive runes. useful to protect some site. place the rune on the ground and forget... when someone walks on it... BOOM!
- ancient ruins with legends about an ancient race... (this is really COOL)
- special secret \"recipes\" that can be used to create special and powerful items
here some suggestions.
If you like that I post more of them tell me ^_^