As some know i still keep tabs on the world of borecraft by checking in on mmo-champion. When i left WoW i stated that whenever a new game that threatens their grip on gamers comes out, they release new content.
In patch 4.3 they effectively kill (I mean end) cataclysm by releasing Deathwing clicky . Knowing blizzard's approximate time frame on patches (from being a lemming and really looking forward to them)...you can bet it will be around the time that KoTR and GW2 have announced their release dates. The fact that they are announcing it now, 4 months(ish) from KotR's release is a pretty good indicator it will be on PTR within the next couple weeks and probably released the day before KoTR hits shelves.
You can call it smart business sense if you want, cause honestly it has been a good formula for them, but with them losing another 300k subscribers over this last quarter they really don't have a choice but to try and get lost subscriptions back by the end of the year as losing 1-2 million to KoTR would really make their board of directors start to shit major bricks.