I've found with hotwire it makes sense to check on a regular basis so you can work out when there is a good offer. It really depends on when a particular hotel decides it needs to hit a certain occupancy level and will cut it's price in order to hit that level.
I just checked for the first week of August, there was a 4* hotel in the WDW area for $129 a night, a 3.5* one bedroom condo unit for $139 a night and a 3.5* hotel for what seems an excellent rate of $44 a night.
IMHO if you wait you should get a rate of below $100 for a 4*, but you need to check on a weekly basis. If you don't mind dropping half a star I would say that $44 a night looks about as good as a deal as you're likely to get.