Michael Jordan dropped in at Chicago’s Marshall Metro High School yesterday — to be principal for a day. “This is the biggest thing that’s ever happened to this school, including when Oprah came 10 years ago,” said Carol Rolowicz, who teaches consumer education and American history.” The 1,150 students were awestruck during a morning assembly when they discovered that the 6-foot-6-inch man seated in front of them was ol’ No. 23. “I can feel the love in this room,” Jordan later told Rolowicz’s class.