Most of you are partially right. But what you haven't reported is the fact that the current castle is going to be lifted out of the park via levitation. Sigfried and Roy will actually perform the act followed by a show featuring a white "Tigger."
The imagineers have been working hard to loosen the castle from it's foundation in order to allow it to rise from the ground. Contrary to everyone's speculation, the original castle is actually inside Matterhorn Mountain. On May 4th, the Matterhorn will be gently tipped onto it's side. The top of the mountain will actually be submerged into the submarine lagoon. This will reveal the castle inside. Sorcer Mickey will re-enact his Fantasia sequence drawing the castle out and it will roll to it's home.
Once the castle is secured, the drawbridge will lower and just like he did in 1955, the now 103 year old Walt Disney will walk out from the castle and shake Roy's hand. He will then give Ei$ner a savage beating with an Angels baseball bat and Roy will help him throw Michael into the castle lagoon where he will be eaten alive by the toxic blue water.
Why does the park have to be closed for all of this? I would love to witness it. Since May 4 is my birthday, it would be the greatest gift imagineerable.