We've never been on a New Years cruise either. But I took my wife on her first cruise in April 2008 and she couldn't wait to go on another cruise. We've gone two other times since then. I've only cruised on Carnival and each one has been a lot of fun and very relaxing. As for what to pack. Tampa will be chilly in December. The ship leaves at 4 pm, so I would expect to be wearing a jacket. The wind on the outside of the ship can be very cold at night. Once we get further south it will be much warmer. For touring we usually wear shorts and comfortable shoes, especially if we are going to be walking. Dinner dress, other than formal nights, we usually dress casual. Formal nights are as formal as you want to get. I've seen people in elegant gowns and tuxedos, I prefer a suit or a coat and tie. Hope you enjoy your cruise.