Way to miss the point entirely.
I understand what you're saying, but it's false reasoning, pure and simple. Proving one part of that video doesn't make the
connection between all of the phenomenon true, nor does it even lend
credit or
merrit to the videos.
If I told you that pancakes, unicorns, the color green and the Halo game series were all connected to the end of the world (and threw in some mightily vague Biblical references to support it to boot), then I
proved to you the existence of pancakes, would you take the theory more seriously?
That's essentially what these people have done. They've taken these almost completely unrelated (and some imaginary) phenoemena and
created ties between them.
You can take it seriously if you'd like, even after the planet is discovered (if, in fact, it exists). You can take it seriously until 12/21/12 comes around and the creators of the video(s) jump out and scream, "April Fool's!" even though it's December.
(Which, when you think about it, makes more sense than their, "theory.")