The New York City Ballet will open its 2010-2011 season with its first fall run to start on Sept. 14 at the David H. Koch Theater. The season will feature 28 different ballets. Highlights include choreographer Benjamin Millepied’s New York premiere, Patti LuPone’s NYCB debut in Lynne Taylor-Corbet’s “The Seven Deadly Sins,” and Peter Martins’ revival of “The Magic Flute.” The season will also feature 13 works by George Balanchine, including the indispensable “George Balanchine’s The Nutcracker,” to begin Nov. 26.