Have seen this reported on a couple sites since yesterday, but nothing official I can find. From WDWMAGIC.com:
Disney introduced a major change to table service dining back in October 2011 when it began to enforce a $10 per person penalty for failing to provide 24 hour notice of a reservation cancellation. Previously this policy only applied to signature restaurants, but Disney will now be applying the policy to all table service restaurants at Walt Disney World.
The new cancellation policy will come into effect on October 31 2013, when guests will be required to provide a credit card for all table service reservations. A charge of $10 per guests will then be automatically applied if a cancellation is not provided at least one day in advance.
In the case of pre-paid locations such as dinner shows, the entire amount will be retained in the event of failing to cancel. The new policy also applies to non-Disney operated restaurants.
Cancellations can be made on the Disney Dining website, at guest relations, a restaurant podium, or via a special phone number at 407-WDW-CNCL. To avoid the penalty, the cancellation must be made up to 11:59pm on the day before the reservation.
Disney has been trying to reduce the number of cases where guests book multiple restaurants, then simply do not appear at several of their reservations.