Details have not yet been finalized, but Disney will begin transitioning to a new reservation system sometime in the late summer or early fall. As a result, Disney will only be accepting Advance Dining Reservations up to 90 days in advance starting around August 1.
The reservation window starts growing again once the move to the new reservation system is underway, and Disney expects to be back to the full 180-day window sometime in the fall of 2009.
We’re told that this does not affect any existing reservations. We’ve also heard (but not confirmed) that Cinderella’s Castle, Chef Mickey’s and Victoria and Albert’s will still have 180-day windows.