Some aaa offices offer some tickets at a small discount from Disney prices. People have recently mentioned a small discount on one of the year passes I cant remember which one if it was the seasonal, ap, or both. But remember not all offices offer this. These discounted tickets can not be used in package deals.
AAA membership gives you if available a 10-20% (this year, next year will mean new deals) discount off your room, or the room portion of a package. The discount varies from season to season, and resort category. To get a room disount you can book through Disney or AAA, or I think any other TA. To get the discount with a package, you must purchase directly through aaa. They are the only ones who can make that happen. An AAA discounted package is full price tickets (same as disneys advance purchase prices), full price dining (if you want it), and discounted room all booked together as a package. You can not combine any other offers with it, but if a better offer comes out they can adjust your reservation for the better deal instead. If you already have a package booked you can contact your aaa rep about signing your package over to them, they can tell you what to do. If they are unwilling, see if they can get you the same packge then cancel the Disney package - if you are still 45 days out there won't be any penalty.
Also aaa is right now offering a special storytime with a disney character in MK. We did this last year and loved it. Very small and intimate. You also get a Diamond card which gives you a small discount at some disneyworld shopping and a Diamond parking card which allows you to park in a special lot at the parks. This parking is something akin to the handicap lots and is usually about the closest parking to the entrance. You also are elligable for a discount on tours with a aaa card...although I just booked my tours and the Disney Visa gave a larger discount.