We had good luck booking right at 7 months for our August 2012 trip. It seems like in 2013 more folks were having difficulty trying to get June and early July.... and people were having better luck with August.
If you are online right at the crack of dawn when your 7 month window opens up it should be a better chance than for June... or say this coming Christmas time (which we were hoping to do, but airfare to Hawaii is crazy at Christmas time right now, so WDW it is).