I don't have any specific information about a Michael Greenberg who is a very popular New Yorker. There could be many people with this name, but without more context it's difficult to know which Michael Greenberg you're referring to or why he would be particularly well-known in New York. If you have additional details about this person's profession, accomplishments, or why they might be considered popular, I'd be happy to try to provide more relevant information based on that.