Damn that was a relationship bomb episode that both highlights what's become good and bad about the show.
I started watching the show because it simply assumed that its viewers would get the many scientific and nerd culture jokes and i believe many did. I enjoyed them very much because it was a little bit different in treating its viewer as intelligent and knowledgeable and didn't linger in explaining the joke.. you either got it or you didn't.
However any show or basically anything that doesn't evolve is doomed to fail but BBT did that really well when they introduced Amy and Bernadette to widen the scope and both additions proved very funny once they found the center of the character. However by this point the show was a ratings juggernaut and has broken well into mainstream so what made the show unique got less attention if favor of relationship humor (which was still very funny).
You can accept that it's still a very funny show or that it has lost its roots, an argument can be made for both sides.
However this one went full in and changed nearly every relationship.
I love Amy finally standing up to Sheldon and pulling the cord on their relationship, that was past time and at least for me it stood for all the friends finally showing Sheldon the red line.
However Sheldon being prepared to propose came as a really big shock (a good one) because no one expected THAT to happen so soon (IF they go with it somehow imagine the wedding night

).
Sheldon's unwitting hand in Penny's and Leonard's relationship also proved quite fruitful as he forced them to ask "hard" questions and finally move forward (loved the moment when Penny realized she really loves her little fella and proposed the Vegas plan). It was marred a bit by Leonard's confession which i felt was unnecessary and the storyline made little sense in them running away without all of their friends to attend the wedding (i'm sure they would have loved a road trip to Vegas). We'll see what happens next season.
Raj and Emily was the weakest development because they returned to the comfortable "Raj is a pussy"part of his character. I'm sad that Emily is apparently on the way out of the show because she seemed like a fun character, the actress played it well and is so hot (redheads!

). I hope Raj finds the balls to either confront her and talk it out and be a man and end it. I'm sad that they didn't make her a permanent character.. i'd love to see her dark side clash with Sheldon.
Howard/Bernadette vs. Stuart was the weakest link, it seemed like they couldn't come up with a good story revolving around personal relationships and didn't want those two sit the finale out.
Anyway.. a very good finale that moved nearly all relationships forward in a big way and i can't wait to see some of the resolutions, especially Sheldon and Amy.