This year's Black Friday won't be so sunny for the nation's retailers. Black Friday the first shopping day after Thanksgiving and the traditional kickoff to the holiday shopping season is often the day that nudges retailers into profitability for the first time of the year. Black Friday doesn't forecast holiday sales but is often a good gauge of shoppers' willingness to spend. Last year the weekend after Thanksgiving totaled about 10% of holiday sales. This year isn't looking good amid the credit crunch and declining consumer confidence. Many retailers stress sales in an effort to get what they believe ...