Borel to ride Rachel Alexandra, its official?

its official Borel has chosen to ride Rachel Alexandra in the Preakness Stakes. this has to be the first time a Kentucy Derby winning jockey has chose to not ride the Kentucky Derby winner in the Preakness and instead ride a different horse. he said Rachel Alexandra is a once in a lifetime type of horse and he couldnt p up on that. what do you think of his choice and what does this tell us about Mine That Bird? do you think Rachel Alexandra is a once in a lifetime horse? anybody wanna take a stab at who will replace him aboard MTB?