My Take on the Finale

WARNING: MAJOR MAJOR SPOILERS. DO NOT READ IF YOU HAVE NOT SEEN THE FINALE YET.

So ... that could have been much, MUCH worse. I am currently breathing a sigh of relief.
As with all season openers and finales, it felt a little rushed, but by now I expected that. But it was very enjoyable, and I think the whole "main character becomes a princess" deal was handled very well. In order to keep my thoughts from haphazardly jumping all over the place, I'll go through it linearly:

Right off the bat Twilight starts singing a song about how nothing could possibly go wrong. Gee, Twilight, I thought you were being crowned because of how much LEARNED. Have you no knowledge of the karma of the fictional world? Of COURSE something is going to happen if you say that! It was a very pretty song, actually, and it was a great opportunity for the fans to see how much Twilight really considers Ponyville to be "hers," a place she's grown to love. We also get a lot of minor-character appearances along the way.
And then it was ended by a practical joke by Rainbow Dash. BUT WAIT. Like everyone on this side of television screen knew was coming, mega disaster: Rarity has RD's cutie mark! And so it begins. A perfect way to open an episode, I thought.
After the theme song, we start to realize what's happening. A LOT of new canon about cutie marks is established. Apparently the physical mark and a pony's destiny are so intertwined that switching the mark alters the pony's true self to the point where they don't even remember ever being anything else. But what's interesting to note is that something very different from "The Cutie Pox" is happening here. Whereas the sort of cutie marks Apple Bloom acquired gave her a bunch of different talents, the Mane 6, save Twilight, are totally AWFUL at the things they're supposed to be doing. I know there was a lot of speculation about how in the world are they going to do two storylines in one episode, and it DID feel a bit smushed, but this really sets the stage for Celestia's talk to Twilight about destiny. It's presented in a very beautiful way here: that your talents are an inherent part of you, and you reach your full greatness when you are doing what you're meant to do. Not that your destiny is something determined BY your cutie mark, but that each pony has a very important place in the fabric of life. All of ponyville was in shambled simply because five of its citizens were trying to be something other than themselves. It was a pretty deep message to explore, and I loved it.
Back to the sequence of events, we get to see RD totally overwhelmed by Fluttershy's animals. Wow, they really got stuck with their opposites, didn't they? The writers chose amusing switches. And then Rainbow Dash starts singing! Woo! More music! About now we realize this is going to be a totally musical episode, which I think was a great way to handle cramming in all of the storyline. You can say things a lot more efficiently in song. So where is Fluttershy? Stuck with Pinkie's cutie mark. Uh-oh. As an introvert, I understand how much stress she must be in. Again, note that the cutie mark does not make Flutters funny. She is totally failing this. So Pinkie Pie is trapped on the farm. (Wouldn't the rest of the apple family have told her she was in the wrong place? Ah well, time constraints.) And we see that her hair is flat. I think she looks adorable with her hair flat. ANYWAY, so that means Applejack ... Seeing her trying to make dresses was hilarious. And Rarity's pretty awesome if she can make the weather change that much with only her magic.
Moving along, after these amazing vocals, we get an explanation. A letter from Celestia? So THIS is how it ties in! This is surely a test. And right now our little Twiley is failing. Think, Twilight, think! Aha! Get them to start doing what they're meant to do, and they'll realize their true place in the universe! Brilliant. And oh so meaningful. I've said it before and I'll say it again, I love the deep themes in this episode. Go, Twilight, go! Don't let Fluttershy leave Ponyville! Go save Rainbow Dash and find your destiny!
RD is ... going to be eaten. I laughed at this part. A little vicious, don't you think, Hasbro?
"I don't really know anything about animals ..." If only she knew, right? And so we see how Twlight's plan works. The memories shooting through her eyes were really cool. I thought at first that was too quick, but then I remembered how much they still have to fit in. And another song! Yay!
I think it was hilarious how the citizens of ponyville were actually GLAD to have Pinkie Pie back. You never know what you have 'til it's gone, am I right? I loved how ALL of the Mane 6 got their "my true destiny!" moments. They weren't overshadowed.
And so Twilight realizes how to fix the spell, and we get big Elements of Harmony awesome magic. Oh, great. It's going to turn her into an alicorn, isn't it? How cliche-
THEY VAPORIZED TWILIGHT! WHAT--
Oh. Oh, she's in some sort of mystical star place. For a minute there, I was worried it was going to be the old "all the magic makes her a princess" that happens almost every single time in television and movies. But it seems there's more to this than meets the eye.
Here we have a scene that takes place in a world we barely get any explanation for, but that's what makes it so amazing. Is this a different realm? Inside Twilight's memories? In a secret dimension? Wherever they are, the memory screens floating by are amazing. And we get to here Celestia actually sing.
THANK YOU, Hasbro. Also, Celestia's speech was wonderful. I felt this scene really delivered, emotionally, and how Celestia was so mysterious. I also loved how the "transformation" took place where no one could see it, not in the sky or something else more cliche.
"A new flying buddy!"
"I didn't even know that was possible."
"ALICORN PARTY!"
Perfect reactions from the Mane 6. Rarity pointing out the improbability of it made it feel real, also. (And when Pinkie got out the confetti I really thought there was going to be a ridiculous song.)
"Is there a book I can read on being a princess?" Oh, Twilight. See, fans? She's the same person. The cutie mark-switching showed us that personalities are more than the roles you fill. I feel as if Hasbro was reassuring us the whole time.
Now, when they bowed down, I cringed a little. I feel as if she should have told them to stop. But the rest of the scene, I thought, went over well. The future is only opened up a little here, and we'll get to see where this goes in season 4. Personally, I'm excited. There's so much they're not telling us, and so many positive things that can happen. The coronation was beautiful; I loved the Mane 6's outfits (I think I love when they go to Celestia's castle only because of the pretty dresses) and we get to see a touching moment between Twilight and her brother. "Liquid pride ..." Sure it is, Shining. You keep telling yourself that. Twilight's parents! Hasbro, you remembered them!
And there's the bookend: episode ends with Twilight saying everything is fine. Didn't she learn the first time? I feel like Rainbow Dash should have actually splashed water on her at that part. That would have completed everything with a nice little bow on top. It did feel like it ended too soon, but as a Twitter comment has stated, we won't get to see what really develops until later. But there was nothing in the episode to indicate that she would have to leave her friends.

I'll conclude (wow, I'm wordy. Sorry for that being so long) by saying that I loved how what made Twilight a princess was her character. She's certainly not of the royal bloodline, but she has a princess' heart. I think it was a great message for the little ones. All of us girls are princesses if we're honest, loyal, kind, generous, and joyful. And some people might resent this, but I couldn't help but compare Celestia crowing Twilight to God crowning all of His princesses at the End of Time, and her getting her wings to us attaining our Heavenly destiny. I don't think that was Hasbro's intent, but it certainly moved my heart. I give the episode my thumbs up. On to the future!