The 20th century saw far greater catastrophes than September 11th, as bad as it was, and they didn't render literature or art or music irrelevant. In fact, I think that literature and art help us to understand - sometimes they provide narratives and metaphors for understanding history, for understanding recent catastrophes.
What I'm nostalgic for is the idea of an edge in New York. There used to be these fringes of the city where civilization sort of ended, and therefore young people could live cheaply, or open nightclubs or art galleries, or even squat. That fringe moved out to New Jersey and Brooklyn. The whole idea of the metropolis is the centralization of like-minded souls, and when the central real estate becomes too expensive, the dreamers, the young poets, and the artists will go elsewhere.
A modest critique of an age in which an actor is the President, in which fashion models are asked for their opinions, in which getting into a nightclub is seen as a significant human achievement.