Someone pointed out that, while we don’t have a ton of data to estimate with for classic, the time between pre-patch hitting the ptr and going live for tbc was 12 days.
Using TBC as a template, the wotlk ptr went live on the 4th so 12 days would put it on the 16th of August.
But again, we don’t really have much data to use to get a good average with so who knows when it will actually hit. I do hope Blizz says something soon though.