We didn't even need the voice over, the beauty of having Jensen Ackles act (aside from, you know, the beauty) is that he's got Dean's emotional state written on his face in capital letters. Big, bold, capital letters. Dean is more broken than he'd ever been in his life, and the one single thing that kept him from putting a gun to his head is the promise he made to Sammy. And he would always honour promises made to Sammy.

Why yes, I am firmly camped in the field under the "Sam and Dean are soulmates" banner.

Absolutely. I look forward to it. :D