The stretch of Camperona (murito, 8th stage), Naranco (9th stage), Covadonga (10th stage) and Cabarga (murito, 11th stage) will be crucial, not only for Contador, but the entire race. I doubt today's climb is hard enough to make a difference. If he loses non-semantic time today, its probably already over before it has begun. He can't make 2 minutes up on everybody - someone won't fade.