I got this from WDW News Today:

Reported by the Dis:
Disney will begin implementing a new reservation system that combines dining, recreation and tour bookings.

The conversion will start on July 21, 2008 and is expected to be functioning on October 24. While this is taking place, the latest dining reservation date which can be booked in advance is January 25, 2009. Once the new system is operating, it will revert to the 180 day Advance Dining Reservation window.

The exceptions to the shortened ADR booking window are Cinderella’s Royal Table, Chef Mickey’s and Victoria & Albert’s.
This updated system has been in the works for a while and is now finally being implemented. The rate of error from the old system necessitated the changes and the new system should work much more efficiently than the old.