I just researched abit to try find the actual announcement month, and I got it in september (If November), and October if December-release.
I found out that WotLK was approximately announced 2 months, and week before the release date (Source: http://news.cnet.com/wrath-of-the-li...ate-announced/ ), and TBC was announced with the same timespace between release date and announcement (Source: http://www.gamershell.com/news_34222.html ).
Which led me to the thought that the release date WILL come next month or october if they hold their "This year" politic. My current bet is BEFORE Blizzcon (22-23 october) with a mid-December release.
What do you think about this? Could it be right / wrong, and what are your suggestions for a announcement of the date.