Hi Chris!
The best answer I can give you is to actually refer you to a site called Mousesavers. On their site, if you search for "historical discounts" you'll find a page that give all of the discounts for the past few years. The invaluable chart lists when the discounts were announced, who was eligible, any restrictions and when they expired.
With the data there, its easy to look back and compare a few years to see if the dates you're looking at typically have discounts or not. While its not a guarantee that 2012 will see the same promotions, its a good guideline.
Another great resource is to keep an eye on the
Special Offers page of DisneyWorld.com. Right now there are some discounts through March 2012, so you may want to check it periodically.
Hope you can find a great deal!