My DBF and I were in Disney about 3 weeks ago. We went down there with reservations at Crystal Palace, Biergarten and Ohana. While we were there we were able to get reservations the remaining nights at our first choice restaurants (Spoodles, Chef De France, Raglan Road and Tony's) by calling either the day before or the day of. We are pretty flexible with restaurants, but it really was not hard to get good times at places we wanted to eat at!! We have done this before and have had good luck in previous trips. It is always worth a shot to call while you are down there if you didn't get the ADR you wanted, you may be surprised the type of availability you can find.
Good luck with your ADR's and have a great time!!