If you are qualified for the 7 for 4 plan that is an AMAZING deal and yes I would book it right away!! (if it works for your travel dates of course) If you at least have it booked you can change your mind later if something better comes along (not likely) but then you will at least not lose on the chance to take advantage of this.
About the only other way I know of to get a great deal is to buy an annual pass. Even if you don't plan on going back to Disney anytime soon, you can save up to 35% on room only plans. But the rates don't come out very far in advance. For example sometime in the middle of this month they will release the April, May, June rates, so it could be several months before they release October ones. And they are in limited availablility so there isn't a guarantee you would get one.
Do check out the resorts board for lots more information!
Brenda