You can upgrade your dining plan to a more expensive plan for a fee. Another post on the boards gave this info:
Quick Service to Regular
Adult: $19.02 per night
Child: $3.13 per night
Quick Service to Deluxe
Adult: $65.30 per night
Child: $13.76 per night
Regular to Deluxe
Adult: $46.28 per night
Child: $10.63 per night
The free dining dates have not been officially announced for December yet. Rumor has it that December freed dining will run Dec 12-23, but that's just a
rumor, nothing's official yet.
Value resorts would get the quick service dining plan free, Moderates/Deluxes get the regular dining plan free.
You might want to follow this post for updates:
http://www.disboards.com/showthread.php?t=3261805