Another great episode, though the finale isn't quite the cliff-hanger season 3's was, it was still an amazing ride.
My favourite part as morbid as this sounds was Gus walking out of the hospital room adjusting his tie, for a minute there you really think he's invincible.
I suspected Walt poisoned Brock from the minute Gus didn't get in his car last episode. I felt it was a giveaway, you could almost see him putting it together, Jesse telling him Brock was poisoned, Gus knowing it wasn't him that poisoned Brock.
That tip of the hand was the only thing that kept this episode from a perfect 10. It made the final shot a little anticlimactic for me. But given even that, it was still an amazing ride, even figuring what the twist was it was still worth it to watch Walter's reaction to every revelation and every move.
As far as I'm concerned the only question left is, where's Mike?