Currently they are updating the ADR system.
You can make reservations up through February 22 right now.
Beginning on or about November 21 they will be done with the upgrade and will open the window back to 180 days. So on that day arrivals dates from February 23 - May 20, 2009 will be open.
The exceptions to this are Chef Mickey's, Cinderella's Royal Table, and Victoria & Albert's. Those three are remaining at 180 days throughout the update process.
Sometime after the update they will allow online booking, but the official date for that has not been released as of yet.