No one is quite sure who's behind a mysterious new website promising "an October Surprise that will change the 2012 election," but that hasn't stopped people from guessing.

So far, very little has been revealed besides a claim that one of the candidates "isn't being honest," which is no surprise.

However, the person or persons behind the site say the content that will be unveiled at precisely 5:30 PM ET on October 22nd has been verified by a "rock solid" source and is "irrefutable."

Among the most popular speculations currently being floated are Romney's elusive tax returns or something damning involving President Obama and Libya.

The former stems from the suggestion made by some that one of the blurry "teaser documents" posted online resembles a tax form, and another possibly features a Massachusetts State letterhead.

The latter was prompted by a hint dropped on the site's official Twitter feed claiming the subject of the "surprise" was "mentioned in both the VP debate and second presidential debate."

Then again, at least one Twitter user thinks this is all a viral marketing campaign for Animal Planet's "pet election."

UPDATE: This Fark comment from a user claiming to have successfully linked the October Surprise site to a rickroll prank from 2007 is getting a lot of attention.

The part about the alleged creators working together at Discovery could still support the pet election hypothesis, which is the one I'm personally rooting for.

UPDATE 2: Discovery Communications developer Jeff Hopwood confirms his involvement in creating the October Surprise site, but says it was commissioned by a third party, and claims he doesn't know what the surprise is (though he guesses it could be a viral marketing campaign).

UPDATE 3: So, yeah. It was a rickroll after all. Good one?

[screengrab via OctSurprise, documents via BuzzFeed]