Depending on availability (only a certain number of rooms are released for each specific discount), it should.
We initially got a quote for the CAA rate (same thing) for the last week of August '08 - until we got the 20% code from Disney and decided to do the bookings ourselves rather than work through the agency. We wanted a package, and you can only book a package with the AAA rate through them - not Disney. If you only want to book a room, you can do this through Disney directly. Call them and see if there is availability - but have your membership number ready, they often ask for this over the phone.