LONDON (AP) ??? Prince William is joining stars such as Ian McKellen and Cate Blanchett on the red carpet in London for the U.K. premiere of The Hobbit, the first part of Peter Jackson's The Lord of the Rings" prelude.William's pregnant wife, Kate, is missing from the prince's arm ??? she cancelled her appearance at the premiere due to acute morning sickness.McKellan, who plays the wizard Ganda