One of the untold stories of the success of the NYC housing market of the last decade (obviously separate and apart from the credit boom) was the attention to detail. In the early 1990s my relatives in the midwest saw NYC as a scary place with tourists getting stabbed on the subway, graffiti, homeless everywhere, city services a mess and public spaces in disrepair. I grew weary of “New York Bashing” in the media. In 1991, my father was mugged twice in broad daylight on a weekday afternoon outside of my old office on 45th and Fifth Avenue.
There is a great article by George L. Kelling in City Journal called: How New York Became Safe: The Full Story A citywide effort, involving many agencies and institutions, helped restore order. 
New York City figured its way out of a seemingly hopeless situation. Young families were fleeing to the suburbs in droves. I always viewed this success through the lens of the efforts by NYC government, but thats only a party of the story. Many individual organizations focused on their own turf and made a difference.
I feel that this laid the ground work to stem the exodus from the city, improve city revenues and encourage residential development.
In sum, a diverse set of organizations in the city—pursuing their own interests and using various tactics and programs—all began trying to restore order to their domains.
My concern now is that severe budget cutbacks and a weak economy could undo many of the gains in the improvement in the quality of life many living in the city have experienced. This was a phenomenon also seen in other metro areas, but in my limited travels, more of the improvements of the past decade were a result of the credit boom whereas the boom in NYC began in the late 1990s.