Why hasn't my package left louisville, kentucky?

They shipped it on monday and it has an estimated delivery date of wednesday 3/16/11 which is tomorrow. I chose 2nd day air from ups. The package arrived at louisville at 12:49 PM on 3/15/11 and it is not 12:22 CST and it has not left kentucky. Can i expect for it to leave within the next couple of hours and have it delivered tomorrow or will it get delayed?