I was about three episodes behind because life got in the way, but now I'm caught up, and glad that I am. It's all very, very good.
In terms of this last episode... I'm pretty impressed, but not to the extent that other people seem to be. I actually liked the previous episode more, with the scene where Jack and Todd and company show up to the standoff. That whole scene, the build up, the execution, everything, was perfect. It was obvious that Hank wouldn't get out of that alive. In fact, that was kind of obvious from the moment he said "I love you" on the phone with Marie.
More than anything, I think I'm surprised and a little saddened by how human and fallible Walter has been in these episodes. Hank beat him, and Walt had no way out of that situation. He had given up, he was handing himself over. He also showed the importance of family to him. If anything, these episodes made me see Walt as less of a monster, because he couldn't even consider killing Hank as a way out. But Hank dies, and Walt loses most of his money on top of that. Throws Jessie under the bus in an attempt to lash out, and then loses his family too. Throughout it all, he has just been reacting to events, again and again, never in control the way he was in the past. Which is probably telling, and stems from his overall psychology, but it's still disappointing from the perspective of a spectator, since seeing Walter as Heisenberg is one of the best parts of the show.
My theory for the future: once Walter calms down and realizes everything that has happened, and that Jessie is being used by Todd and Jack to cook meth, he decides to come back and save him. That's what the machine gun and ricin are for.