Regarding the Earl of Sandwich...last time I was there in October 2010 there was still a 15% discount. On my website for AAA Carolinas, under the Travel tab there is a link that indicates "National Savings". I'm getting an error right now but I believe this is where I took the zip code to DTD to see what AAA Benefits were in the area. Hope this helps.
Disney-operated restaurants at WDW don't give AAA discounts. So you won't find them in the parks or the Disney resorts. Some restaurants at the Dolphin will give you a discount with an AAA card (Picabu, the Fountain)
During my families most recent trip to WDW which was in December 2010 we still got 15% off at Earl of Sandwich by showing our CAA membership card, which is our version of AAA and the exact same thing.