Fall means the start of a new TV season and for the first time ever, the start of a new season of So You Think You Can Dance. Just five weeks after wrapping up Season 5, Nigel Lythgoe, Mary Murphy & Co. are back Wednesday (8/7c, Fox) in search of Jeanine Mason's successor. "I think it's good for our fans that absolutely go through withdrawal and write me by the thousands: "Oh, I can't believe it's over! I can't wait 'til next