While they do stop some of the live Christmas shows after Christmas Day, the decorations are out in full force until after New Year's Day. They start taking them down January 2nd and by a few days later, they are completely gone. You should be fine on NYE.
Allygirl, I asked the same question last week and was told it is still in full swing on new year's eve. Then they are almost completely gone in two days! If I may piggyback your question, I forgot to ask when they start putting up the decorations? I assume it's after Thanksgiving but I'm just curious to find out how long they extend the holiday on both ends Have a great time...I did Universal Studios for two years on NYE and it was an absolute blast that time of year