I think the technical definition of "story now" is not very good.BW delivers little "n", normal "narrative" in spades. I'm not sure it really hits Story Now according to the technical definition of the term. (I'd say it hits the practical definition of what Story Now ought to be, but that's another discussion.)
Ron Edwards, for example, classifies Dying Earth as a narrativist game - correctly, in my view - although it doesn't fit the technical definition - it is not about addressing a "theme" as Edwards' defines that term. The goal of play in Dying Earth is to set up situations in which you can utter your Vancian "tag line" and thereby produce mirth (of a cynical, jaded variety) in your fellow players. This is an aesthetic focus, not a thematic (in Edwards' sense) focus, but I still think it falls within the narrativist idea: by playing my PC, according to the rules of the game, I will get an experience that is pleasing in a literary/artistic/aesthetic fashion.
What sometimes puzzles me about some posters on these boards - and there's some of it at the moment on the Falling thread - is that they want to try and get the aesthetic experience without using the rules, or somehow regard playing by the rules as at odds with producing that experience. Maybe it's just my Forge-influenced prejudices, but I see this as a sign of having had one's spirit crushed by too many years of playing games with crappy rules (ie crappy relative to the play experience that you are looking for).
That said, BW is not perfect in its rules, and the designers seem to know as much (although they're obviously also proud of how strong it is in its design). The Adventure Burner, for example, has discussions of how to run fights against solitary antagonists that drives home how strong 4e's elite and solo monster design is in spite of the stunlock problem. And (unless I've missed it hidden in a trait somewhere) BW doesn't seem to have a mechanic whereby morale can be drawn upon to shrug off wounds: you can spend your own artha to do so, but there is nothing analogous to warlord healing (Command can reduce hesitation, but not allow overcoming penalties). Although in typing this up, it occurs to me: should I be getting that warlord vibe by having Command provide helping dice to a Health check to shrug off wounds?