One of the finer aspects of tabletop play was the interaction with a fictional community one could achieve greatness, notoriety, infamy and reputation. I contend that the dungeons and dragons online game would do well to engage this aspect of gameplay.
There would be certain requirements. First, it would be a "solo only" zone. Each individual player would rise or fall in this zone on their own merits. Second, the zone would scale to the characters level. A character entering a zone at level 3 would find it much more difficult when they entered it at level 7. Finally, the quests would be "ongoing", meaning that you wouldn't have a small army of NPCs who would each give you a single quest. Instead you would have one master in the zone who would be suited to your talents and who would provide the quests for you, with randomized lesser quests on the way.
To achieve this end, I propose "Slum Quests". The world of the slum is one ripe for intrigues, gallantry, and exploration. In the stormreach slums a wrong word can bring a swift assault, or the opportunity to diffuse a most difficult situation. The primary Slum quest would be random, the character would be granted a "primary" quest each day and as they traveled within the slums completing these quests, random event quests would pop up. You might be accosted by a woman in need, leading you down into a dungeon to rescue her child from kidnapping kobolds, you may find yourself attacked purely at random by street thugs... unless your bluff... or intimidate check is significant enough to scare away the rapscallions. But not everyone in the slums is a foe, and tabbing around won't give everything away, the innocent halfling selling apples might up and reveal herself to be an assassin sent by a rival house.
These random event quests could easily be taylored to suit the individual in a variety of ways as every aspect of the character is already available for the game to know. A fighter may encounter more thugs, a paladin may encounter more damsels in distress. A rogue would find that their services are necessary in releiving the lord of the manor of his banknotes.... as may a fighter who happened to invest a great deal into hide and move silently.
It would be in this singular zone, a decreipt worn down slum that we would find a cast of characters that would provide these randomized daily quests and events for the single player.
As the character gained fame... or infamy within the zone they would find themselves granted housing... followers... and access to a black market... as well as a variety of other rewards...