The current guess is that it'll be in November:

http://www.ebgames.com/product.asp?product%5Fid=647156

Blizzard gives a guesstimate to it's biggest retailers like EB, but it's just that, a guesstimate. If history holds true it'll be delayed. TBC was supposed to come out in that November time frame to take adavantage of the holiday shopping season, but it was delayed until January 15.

So, it'll probably be out sometime between November 2008 and February 2009. Your shammies will ahve no problem getting to 70 before it comes out.