Narrative RPGs and Advancement
Capes talks about resource management and how the game rewards successful players by giving them more resources, which in turn, gives them greater influence over the narrative. While that setup does provide the Gamist Element that I have been seeking from a Narrative RPG, Capes is still lacking any form of mechanical advancement to reward the player.
What do I mean by this? In D&D, after the player successfully navigates a number of challenges with his character, the player earns the right to advance his character and to advance the characters "power". In a pure narrative game (Capes or PTA), a characters "in-game" power can be advanced at an appropriate moment. IE, if you are doing PTA Buffy, Willow can go from cute techno-geek to hottie-Uber witch with no problem. However, the character has not really advanced. The Player has just chosen a new flavor for the same character.
A pure narrativist would say that the advancement of the story is all important. A pure wargamer would say that the control and manipulation of resources was all important. As a gamer though, I say that character advancement and differentiation (I just realized this btw) is also a key element to a healthy and successful long term RPG. I see hints of this in a game like Burning Wheel (but I will diatribe on that system soon) but it is too bogged down in itself. I get the feeling that maybe Shadows of Yesterday (which I have read only once) is on the right path.
Conclusion: In order to have a reliable "campaign style" RPG, the system must have mechanics for character advancement/differentiation. The process of advancing a character mechanically assists in keep a players attention (or at least my attention) and add diversity to the game play and allows players to mold their interaction with the system to their style.