New Year's Eve wedding?

I just moved up to a Nikon D90 from my regular digital camera. It's a really nice camera. My Aunt Grace is getting married on the afternoon of New Year's Eve and her photographer just was in a car accident so she asked me to take her wedding pictures. She will be in the Hotel Pierre in New York and they expect to go down to Times Square at midnight. How do I set my camera so that I can take pictures inside the hotel AND still get good pictures when the ball drops at midnight?

Long exposure at night always do the trick.

Make sure that you have a tripod though.