I'm pretty sure the weird strangled sob noise I heard after that actually came from me, and not Sam. Sad and hopeful is an odd combination to be feeling in regards to the son of Lucifer, but that's pretty much where I've settled on him for now.
Both Jensen Ackles and Jared Padalecki are so understated and so very good in those moments, and I'm so happy the show let the brothers have that moment of reflection and, frankly, despair.