Wow will be released on late september / early octomber, here are some facts:
Cataclysm beta raid testing started: 15/10/2010
Cataclysm launched: 7/12/2010
MoP beta raid testing started: 20/06/2012
MoP launched: 25/09/2012
See the links? well let me tell you, raid testing started durring the half of the beta.
WoD raid testing started: 21/07/2014
Wod beta started: 26/06/2014
Based on this facts we might have wod launch on said dates.
Other facts:
-In the last patch build on beta they updated the brewfest items to wod.
Brewfest starts: 20/09/2014.
-Some people say that blizzard will release wod after blizzcon because otherwise they wouldn't have what to show on blizzcon and therefore ppls would not attend blizzcon 2014. FALSE: Blizzcon tickets are already sold so ppls will go to blizzcon regardless.
-Some peoples say that blizzard will release wod close to christmas to boost their sales. FALSE: As shown on MoP blizzard sold roughly 2 mil. mop games in stores because most ppls preordered a virtual copy + most ppls want to log in as soon as the servers are up