It is expected that David Stone, producer of the unprecedented “Wicked” Chicago production, will announce on Wednesday that the show will ring the final curtain down at the Oriental Theatre following the 1,500 performance on January 25, 2009. By the time that they fly away on their broomsticks, witches Elphaba and Glinda will have cast their musical spells over more than 3 million theatre goers over the 3 1/2 year run in Chicago.