There is free dining for December, but it is a pin code and disney has to send it to you via email or postcard. It has a specific pin code for your name only, so no one else can use it or share it. They send these randomly from their database- i've never received one in all my 20 plus years of going to WDW, this is the first one we ever got and it was in my DH's name to my mom's address (postcard)- weird!? We recently got Disney VISA cards and ordered the custom maps on the disney website- i think maybe that triggered something with our name being updated in the database? who knows. how they choose who they send pin codes to is a mystery. The free dining we got is good through 12/17. (i forget the starting date- after thanksgiving though), plus there were some dates in late october/early nov). However, they only allow a certain number of these discounts to be used per resort, so even if you get a code, it isn't guaranteed it will be available at the dates/resort you want. We just really lucked out this time.
I would suggest ensuring you are in the disney database- go to their site, order the planning DVD, do the customized maps etc. so that it shows activity under your name/registration. who knows if that helps or not, but can't hurt, right?

It saved us $3000 since we applied free dining to 3 of our 5 rooms (10 days worth of dining for 7 adults and 3 kids)!!!!
We are there 12/10-12/20, 5 rooms at WL. Already have our
MVMCP tickets for 12/15 and can't wait for December hours. I assume they will be out around sept 1. We can't wait- see you guys there!!!