Ok... There's a lot of old traveller shows, even a few new ones. Main character is exploring an interesting world, and every episode, somehow manages to find himself embroiled in a situation that just HAPPENS to require (A: Kung Fu, B: Hulking Out, or C: Quantum Physics).
Right now, things are copacetic, because all players can do is hit things with a stick and all that needs to be done is things hit with sticks.
In theory, in the future, PCs will be capable of a vast array of skills, and talking to any given person about the needs of his community won't make any sense if there's 20 ogres that need killing, 14 sick children, 50 fighting couples, a dozen letters taken to each city within 200 miles, 5 muggers, a drought, a cave of mysterious symbols, a possesion, etc.
I think everyone will agree that one of the strengths of DF is that the world feels real. So any system that actually changes the quests available, or a malicious force that follows the player around afflicting character appropriate strife on those around him would break that immersion.
The solution is thus to have all these situations happening and resolving (in a less than ideal manner) all around the PC all the time, and have the hero somewhat isolated from them.
For instance, every time Cain wanders into a city, there's bound to be a few sick people in the city, and a few criminals. Because Cain is a Shao Lin monk and not a wandering doctor, the system tweaks it so that he is embroiled in the criminal activity and not the sick people. (He gets mugged, a fight breaks out in front of him, someone 'randomly' comes to him for help, the mayor lists that as the first trouble when he's asked, whatever).
Obviously, for a living world that doesn't know what kind of character you're going to build/play, there'd need to be a LOT of plot threads laying around (plot threads is used losely here, in the same 'go to this guy's house and kill him' sense we've got now) for all the possible play styles.
The trick would be not locking the PC out of the non-standard plots for his type. Talking to everyone in town, or specificall asking after a certain type of plot (Are there any sick people in town?) should grant access is the 'easy' way to do it.