From someone who's organized multiple meetups in NYC, Hack And Tell being the most well-known, I would say just start the meetup. There's a high probability of lots of people in NYC thinking in the same direction you're thinking, but what you want to do is start letting them know there is a place they can find like-minded people.

Further, meetup will help get eyes on the event. They've been very helpful for my meetups. They're even willing to host them and buy beer / pizza for the attendees.

You'll know within a few months if it's not speaking to people, but more importantly, you'll know if the opposite is true.