Guys.. ANY RELEASE DATE YOU SEE on ANY website is WRONG unless it is on the OFFICIAL world of warcraft website. This kind of thing happened with BC as well, its just people trying to be smart and cool, thinking they know what they are talking about. Believe me, if you visit the wow official site every day you will know that an announcement of that scale will be headline news on their site.
Your second best bet is their forums in the Wrath of the Lich King section.
Third most reliable source will be www.************.com, no not on their forums, on their news page. If they announce something, still look for the "source" button on their posts which will give you a link to where they got it from.