This is taken from the official website of the Tokyo Disney Resort. This covers both theme parks there, Tokyo Disneyland and Tokyo Disney Sea.
Notice from Tokyo Disney Resort
Due to the Tohuku Pacific Earthquake that occurred on March 11, 2011, Tokyo Disney Resort is currently closed. As soon as a decision is made on when the operations will resume, it will be announced on the Tokyo Disney Resort website.
We regret the inconvenience that this may cause and request your patience and understanding.
My heart goes out to all affected by this great tragedy.