Directional Bias For The Day: S&P Futures are lower; The odds are for a down day; watch for the break above 3687.50 for change of fortunes Key economic data report due during the day: Revised Nonfarm Productivity ( 4.9% est.; prev. 4.9%) at 8:30 AM Revised Unit Labor Costs ( -8.9% est.; prev. -8.9%) at…