Is the NYC Marathon still on as planned?

So far, yep! (More here.) The latest from NYRR:

Tuesday, 10/30, 10AM: We are currently focused on recovery efforts, and our thoughts go out to all those affected by the storm. Please stay safe - we will update you later in the day as more information becomes available. Please check hurricane-related news for the New York area and your area, and please check this site frequently, as we will be posting updates. Most importantly, please stay safe throughout this week.