Feb 8 (Reuters) - Almost 50,000 homes and businesses were without power in the U.S. Northeast and Mid-Atlantic region as of mid-afternoon on Friday, with most outages in the Washington, D.C. area, during a blizzard that could drop up to three feet (nearly one meter) of snow in parts of New England. A spokesman for Washington power company Pepco said a tree had fallen on a major transmission line, affecting four substations and knocking out power to some 50,000 customers at one point, though