I always figured it was Luna's place, pre-Nightmare Moon.

Or it could have been the Palace of both sisters, ruined in the struggle.

I was planning on making it the original Canterlot in mine. Luna specifically states in the Nightmare Night episode that she is speaking in the Royal Canterlot manner which suggests that that was where she lived. As the princesses I would keep the Elements close and that was clearlty their holding place so I deduced from that it wouldn't necessarilty be incorrect to call it Canterlot. My plan was for it to be destroyed in the struggle and then for them to build a new palace higher up (closer to the Sun and Moon so Celestia would be able to control both). Would be interesting to see what you want to do with it (assuming you include it at all)

Not sure when I will get round to mine. Might only be able to have the Prologue ready by the end of the month (sorry guys).

As a separate post, what else was worth looking at in that EqDaily post? We have Trixie with some sort of villainous-looking pendant (the obvious speculation from the comments being nega-elements), the Crystal Kingdom, and abandoned ponyville

What do you all think?

It does sound like a cool concept, Trixie's element should be Pride.

I didn't look too much into it but I liked the comment that said "elements of disharmony". 

I like to imagine Discord is in charge and was able to sway the hearts of the antagonists of past episodes.

Gilda- Element of Cruelty

Trixie- Element of Deception

Flim/Flam brothers -Elements of Greed

 etc etc

See I could write a fic too :P

I'd guess that some sort of anti element would be the most likely scenario. I can't imagine them adding in another element of harmony; there are all sorts of problems with doing that. An abandoned Ponyville would be cool to see, but I'd think it would be done in a sort of vision of the future or something. Or maybe as a mid episode catastrophe that is resolved before the episode finishes (or multi part episode, since that's supposedly in the last two confirmed episodes of S3).

Spoilers follow in the blacked out text;

Spoilers! The Crystal Kingdom is confirmed via a new toy line and the second song shown, the Crystal Fair song. My impressions from that is Cadance is somehow involved with them, so they probably aren't antagonists... at least to start with.

On an unrelated note, is anyone here a fan of Star Wars: The Clone Wars? 

Ideally, it would match the mane 6's elements (somehow. Anti-magic?), so you have three of them, plus a few others (Cruelty v Kindness, Deception v Honesty, Greed v Generosity, Misery or Tears v Laughter, Treachery v Loyalty). Of course, it would involve flanderizing a lot of these guys into villains when they really weren't straight evil. As i pointed out before, Flim-Flam bros had a perfectly reasonable deal going in through most of the episode until they decided that they would take over the farm. Trixie was just a show-off. Gilda was pretty bad, but still genuinely seemed to care for Dash (if nobody else)

You underestimate Discord's powers! He was capable of manipulating the elements of harmony  fairly easily (by elements I mean mane six). Manipulating those who already have some form of evil within them should be a piece of apple pie for Discord.

That's all fun theories to be honest. I don't think that will happen. Actually I do, but it's more Trixie focused. My speculation is that Trixie, after being embarrassed and outshined by Twilight, is seeking to become a more powerful magician -motivated by the thought that one day she will get back at Twilight. She eventually bumps into someone who grants her that power in the form of an element (of Disharmony if you will). It's going to be a "sell your soul to the devil" kinda episode. And Discord is the devil.

Well, and since Twilight resides in Ponyville, Ponyville suffers the consequences. OOH! Speculating is FUN!

*SPOILER*

I keep going back to Discord because John De Lancy accidentally revealed that Discord will have a return in season 3

To the spoiler in the above post, that's awesome. He is one of my favourite characters in the show.

New Non-Brony Commentary is up - no idea if people watch these when I post them, but I find them entertaining enough xD