All of this beta rumor stems around a German Assistant Community Manager by the name of Gnorog telling the German gaming site Allvatar that the closed beta was going to be starting on July 3rd. It was "fueled" a little bit more in that Bornakk did not come out and deny the July 3rd date, something that they have regularly done before.
Another small indication that something is changing is that the Wrath of the Lich King forums have seen several sticky post removed. They normally do this only when new information is about to come out to replace said sticky posts.
It will be interesting to see how this one plays out. And if you do happen to get into the beta, feel free to drop us a tip. Happy waiting!