It is choreographed to music and controlled by computers....that's the dancing part. And the music is techno and LOUD! We saw the display last Tuesday and I thought it was great fun. I remember reading about the display at the Osborne home before it came to MGM.
They had snow blowing from the rooftops like at the MK and they were selling hot chocolate from a couple of stands. It's worth a stop. We dropped in at MGM after dinner elsewhere that night because it was an Extra Magic Hours night at the park. We just went straight back to the lights...visited for 20 mins and then went back to our hotel. We could have done a few rides before or after...but it was just too cold.