Back in late 2011, Disney introduced a much needed policy to prevent people making dining reservations that they had no intention of showing up to. Many guests would make bookings for all restaurants every day, so that they could pick one depending on what they were doing that day.
This in turn meant lots of false bookings, and empty tables. So Disney brought into effect a 'no-show' fee of $10 per reservation. This has helped greatly to free up unused tables, however it was never enforced at all locations.
As of October 31, 2013 however, the policy will be enforced at all table-service restaurants. A credit card will be needed when making a reservation, and if you don't provide at least 24 hours notice of a cancelation and fail to turn up, you'll be charged the $10 no-show fee.
For pre-paid locations and dinner shows, the entire amount paid for your event will be kept.
The policy is also going into effect at all non-Disney owned restaurants, such as Wolfgang Puck and Planet Hollywood over in Downtown Disney.
These changes should free up a lot of reservation space for guests who genuinely wish to eat at them.