When you get closer, and they announce the 2009 planning DVD, make sure you order it online. They periodically followup with an email discount code. May or may not happen, or apply for the dates of your trip, but it's worth a try. They gave us 20% for our September trip and we were able to apply it to 3 rooms. My MIL did the same and was able to discount the other 2 rooms.
And, of course, watch this site, MB'ers are among the first to know if there's a discount out there.