David Kelley and his organization are a lot closer to NYC, but Poughkeepsie is just far enough away that The Objectivist Center doesn't have much Gotham City feel to it either, although they hold periodic one-day talkfests in the City. A few people have moved to Poughkeepsie, usually because they wanted to work for the organization, or were in love with someone who did.
But surely vast numbers of Objectivists remain in the city. The potential market is big. Partly the market is old timers, who remember NBI, Rand, etc. Partly the market is younger people who have read the books but who have had little contact with organized Objectivism.
That's part of why I'm watching the new Objectivist Community Center with such interest. Located in midtown Manhattan, operating on a shoestring, the organization simply exudes energy.