The MK was so crowded New Years Eve 2006, that they weren't allowing anyone else in at 11:30 am. It was pretty much locked down for the rest of the day since no one would leave for fear of not getting back in. We ended up in Epcot and it was nice. They handed out hats and glasses, and the size of Epcot made it feel less crowded. We were also able to come and go a couple of time throughout the day without fear of not getting back in. We did however leave before Illuminations (DD has sensitive ears and fireworks trigger massive headaches
) so I don't know about the special Illuminations
.