Yes, I believe AAA discounts are available throughout the year, but there are a limited number of rooms available for each date at that rate. The AAA discounts due to come out soon will be for 2007. (They release the discounts for the entire year all at once.) You didn't mention when your trip will be, but if it is in 2006, yes, those AAA rates are available now. If your trip is in 2007, you can make your room ressie now, then call back when the AAA rates are released & have that discount applied to your ressie.
You can get a AAA discount on your room by making the reservation through AAA, your TA or CRO. You can also get a package (room & tickets & dining plan if desired) with a AAA discount on the room, but I believe the only way to reserve this is directly through AAA. (Hopefully someone can clarify whether this is correct or not. I have never used AAA for a package before, so I can't say for sure that this info is right!)
To make things even more confusing, AAA (or at least our local branch, AAA South) offers discounts on WDW tickets, too. They only have a limited number of ticket lengths & options available, but if they happen to have the ticket you want, their prices seem to be even better than the discount brokers.
Clear as mud, huh?!
Hope this helps a little!