This is JMHO, but I think you will be lucky to get a cash ressie for a 2 bedroom villa at those DVC resorts in early December, let alone a discount.
My advice is to try to reserve one as soon as you can. If you aren't successful right away, keep calling.
DVC members can make ressies beginning 11 months ahead of time, and as others have posted, this time books very quickly. To reserve something in 12/03, DVC members can (and will) call in January, 2003. Consider renting points from a DVC member if you absolutely, positively HAVE to stay at one of those resorts during early December.
Good luck!