Meg -
I already have my departing ticket purchased for a 8/24 arrival also, but I have a late flight so that night was going to be room only. Then I am booked for 8/25 - 9/1 with dining and 40% off at a value. It's just my son and I and the 40% saves us about $200, while
free dining would save us over $400.
Therefore, if free dining comes out I will rebook my package to do 2 nights at room only with the
AAA rate. Then I will need to check back in on the 26th with the package for 6 nights. My park ticket will start 8/26. You can't start your park ticket earlier than the package.
You actually have two options - purchase a park ticket to begin 8/24 or 8/25 and do 2 nights at the room only rate. Then purchase the package with free dining to begin 8/26. If the rules are the same as last year, you will need to purchase a one day park ticket for everyone in your group in order to have the free dining package.
The other option is to do other non park things until your package begins. Fortunately for me, my son and I have 3 water park /DQ passes left over from a non expiring ticket. We will go to a water park on 8/25 and enter the parks on 8/26. We were going to do a water park and DTD during a trip anyway. We will just do them first, instead of in the middle of the trip.
I will lose a park day up front, but it will be plenty of park time in the end.
Having a few free days would also give you the option of visiting seaworld or universal. You could do DTD, Disney Quest, or a water park. I guess you have to factor in how many are in your party, what time of day you arrive on the 24th, what resort you are staying at, and what is the cost for activities outside of the park. Creativity is the key.