We did Epcot on Millennium Eve, and while it was packed, it was also WONDERFUL! I would definately do it again! Plan a PS for one of the World Showcase restaurants, and plan it early enough so you can get a good spot for Illuminations and the countdown. We did end up saving our spot for a couple of hours, and it wasn't a great spot, but it was fine. The other thing to consider when making dinner PS is the time it will be midnight in the "country" your restaurant is in! We were in Germany for a 6 pm seating, and that was also midnight in Germany, so we got caught up in all the reveling!!! It was quite confusing to get seated during that time!