In response to the inquiries of a couple of fellow posters, here are the latest population figures you requested (as of 1 April 2013 census estimates):
Louisville (the old city plus unincorporated Jefferson Co., KY)-605,220
Louisville-Jefferson Metro Government (entirety of Jefferson County, incl. 92 independent cities within)-763,180
Louisville, KY-IN MSA-(Jefferson Co., KY + 11 other metro counties)-1,380,200
Louisville, KY-IN CMSA-(incl. Scott Co., IN; Hardin and Larue Cos., KY)-1,510,200
Louisville (the old city plus unincorporated Jefferson Co., KY)-605,220
Louisville-Jefferson Metro Government (entirety of Jefferson County, incl. 92 independent cities within)-763,180
Louisville, KY-IN MSA-(Jefferson Co., KY + 11 other metro counties)-1,380,200
Louisville, KY-IN CMSA-(incl. Scott Co., IN; Hardin and Larue Cos., KY)-1,510,200