Diane:
The rates for 2013 are due out sometime between now and the end of August ... after that Disney will start offering specials to fill up less busy times.
The downside? July is not really a 'less busy' time. While they sometimes have some offers for that time period, it's the peak of summer vacation for a LOT of families and therefore Disney doesn't have to discount that much usually.
Bottom line? The standard rates for that time period will be out no later than August and after that keep watching for offers and special rates that might cover your travel period.
Knox