Yeah, no way it's happening in June. Maybe if the beta had come out in early January, but not now. I disagree that they'd be aiming for the 10th anniversary for the simple reason that business almost always trumps sentimentality. The sooner the expansion is out, the better for their bottom line. (Not saying they ought to go willy nilly at breakneck speed, but c'mon...)
I think that sentimentality is something Blizzard still holds on to. And expansion on the 10th anniversary is a perfect thing. It also falls within their projected (via pre-order listed dates) release schedule. If they make it by then, remains to be seen. You can't ignore that it falls almost in a destined fashion. November 4th, wow's anniversary date, is on a tuesday this year.