I know it's very odd to think about, but there will come a point, one day, when you will have svcked Skyrim dry (eww). I know, I know, but seriosuly. Main Quest will be gone in a flash, you'll have spent days grinding down the side questions, and all that remains are a few dungoens you haven't explored (and have no real reason to), and the obligitory 'find all the wine bottles' mission you have no intention of doing. Ever. All you're doing now is aimlessly kicking about the world, waiting for DLC to land. Or are you?
See, what would be cool is if we could use Radient Story to possibly 'fix' this. It'd be simple, really; a pool of characters will supply you with seemingly never-ending supply of quests. This are randomly generated from a little pool of options Radiant Story has to play about with. For instance, an NPC could tell you to go and assassinate someone; Radiant Story would choose who, and where, based on where you've been (or, indeed, have yet to visit), who you are, what you've done, and so on. There could be a pool of options, like assassination, fighting, stealing, finding something in a dungeon, and maybe even teaming up with AI to take on even more AI, to turn it into a big battle rather than a one-man thing. It's important to get variation in this, so come up with the most kooky things you can imagine that'd really keep you interested.
PRO
There'd always be something interesting to do in Skyrim. It'd be a great timewaster, and Radiant Story would make sure it's always tailored to who you are, and unique in that sense. It could also throw up some really neat surprises.
CON
There's only so much dialouge/choice in the world. Eventually, these quest-givers would repeat themselves, and give pretty much the same quests, but in a slightly different place. It would very slowly kill the atmoshpere and immersion, and artifically elongate the game, which is depressing to those who feel there should be peace and calm once you've finished the quests.
P.S.: Please no 'we can just mod afterwards'. Remember the console guys.