Haha, there's been one in Discover Mills, in Georgia, forever.
http://www.brothers-brick.com/2009/05/17/lego-store-grand-opening-in-frisco-texas-sets-record-in-sales/Have fun waiting for hours to get inside. It's already open, just go now.
Because that link I posted was totally for the Frisco store.Actually, this is in Dallas