So much for an epic showdown between John Gilbert and the Salvatores.

Heading into this week's season finale, viewers of The Vampire Diaries were led to believe the series had built to a battle for Mystic Falls, one side anchored by Elena's birth father, the other by two of her close, undead friends.

Instead, John's device-based scheme was completed halfway into "Founder's Day" and the attention then shifted to the fallout from it... a fallout whose ramifications will be discussed by fans all summer long. Wow. What a season finale!

Producers had promised us a bunch of cliffhangers and they delivered. Below, we analyze each, culminating in the most shocking event of them all.

RIP, Caroline? First, let us bid farewell to Anna. May she finally find peace and happiness, reunited with her mom in vampire heaven. Will Caroline soon join her in the next life? My guess is no. While this character isn't key to any ongoing storyline, the show would have killed her off last night if that was its intention.

Welcome, werewolves The reason behind Tyler's accident wasn't to get rid of Caroline. It was to push Tyler's transformation further along. To that, we say: hallelujah! In our Vampire Diaries Round Tables, we've been clamoring for more on this individual's apparent affection for full moons. It was teased perfectly on the finale. Tyler won't just have to deal with what he is now.

He'll have to deal with the death of his father. Does anyone else smell the discovery of family secrets and the impending arrival of more werewolves? We know how much fun that has been on the vampire front all season long.

The new Bonnie: I love this evolution. This witch knows who she is now and she's not shy about her loyalties. Might Elena have to choose between her BFF and her BF next year at some point?

A turning point for Jeremy It started with the death of his parents; it was pushed along by the passing of Vicki and his sister's betrayal; and it ended with the murder of Anna. Sick of feeling such pain, Jeremy swallowed some blood, downed some pills and left viewers wondering: really?!?

Will the pseudo suicide attempt really work? Will Jeremy truly go to the dark side in order to alleviate his suffering? On most shows, I'd shoot down the notion that a main character would actually end his human life. But The Vampire Diaries has proven it's unafraid to shock. Sound off in our forum: Will we see vampire Jeremy next season?

Hmmm... am I forgetting any development from the finale? Oh yeah: KATHERINE RETURNED!!!!!

Double the Dobrev, quadruple the suspense The show got me. I thought the finale would conclude with Damon kissing Elena, followed by the latter screaming over Jeremy's unconscious body. The episode was solid up to that point, but it felt like a let down. Ending such an incredible season on the fate of a character that was never central to it? Didn't feel like it would have fans buzzing until September.

Then, Elena grabbed that knife. Then, John cried Katherine?!? Then, my eyes bulged, her face morphed and we were left with the stunning realization: Katherine is back.

Just consider all the possibilities this allows for:

• Damon goes into next season thinking he kissed Elena, which is ironic: just as this vampire discovers his humanity, his first major decision is to hurt the brother that saved his life. If Damon can truly feel now, I can't wait to see how he feels about that.
• Of course, Damon actually got to first base with the woman he's been searching for since the 19th century. When will he find this out? And, while he may have referred to Katherine as a "bitch" last week, are his affections for her actually gone?
• Let's mourn John Gilbert for his moment. Yeah, he's kind of a murdering bastard, but he had his reasons - and he's also Elena's birth father. Can't imagine she deals with his death well.
• Was Isobel behind any of these developments? We know she's in contact with Katherine. Will we see Alaric's ex-wife again, as well? What is her true agenda?

Indeed, it was a stunning conclusion to what had been a somewhat meandering, disappointing episode. But that all changed with the thrust of Katherine's knife.

There's no new episode to tease for next week, so we'll just ask readers: How loudly did you scream when Elena kissed Damon? Do you feel jipped that it was actually Katherine? Or just curious and excited that she's back? Sound off now and consider the following Vampire Diaries quotes from "Founder's Day."

Damon: I'm not a hero, Elena. I don't do good. It's not in me.
Elena: Maybe it is. | permalink

Damon: Somewhere along the way, you decided I was worth saving. I wanted to thank you for that.
Elena: You're welcome. | permalink

Bonnie: You saw what I was able to do tonight. I know who I am now. If Damon spills one drop of human blood, I'll take him down. | permalink

Damon: Life sucks either way, Jeremy. At least if you're a vampire, you don't have to feel bad about it if you don't want to. | permalink

Jeremy: Even I can't remember why, I still feel empty, alone. Making me forget won't fix it. | permalink

Stefan: I try so hard to hate him, I guess it's just pointless.
Elena: You care about him, so do I. But I love, Stefan. | permalink

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.