The Saturday before Christmas should officially be renamed ''Black Saturday " as retailers slash prices and offer incentives to lure last-minute shoppers. It’s all part of an effort to save what's left of what the Wall Street Journal calls “disastrous holiday season.” Across the country many retailers are extending store hours and offering sale prices better than Black Friday the Friday after Thanksgiving and unofficial start of the holiday shopping season. Barneys New York is cutting prices by as much as 70%  Circuit City is planning unadvertised specials on big-ticket electronics JC Penny (JCP) will offer approximately 300 door-buster discounts and ...