Okay, normally, I just go ahead and ignore these silly end-of-the-world theories, but this one is implausible even by the usual pathetic standards of end-of-the-world theories. It's seriously ridiculous.
Here's their justification, for anyone who hasn't read up on it yet (you're not missing anything): They take a biblical metaphor, that a day is as a thousand years to God, and apply it literally to an estimated date of the great flood. Because seven days were mentioned at one point, they added 7000 years, arriving at 2011 after perfectly valid year-based mathematics. Except that the flood, according to the Bible, already happened and ended, so the prediction about the flood would have already been fulfilled.
Make no mistake -- this is a cash-in by a particular religious group. ALL of the public "service" announcements about this originate from the same group, with their website plastered on it. It's a publicity stunt so they can sell more pamphlets or whatever.
Anyone else up for a world where anyone who tries to spread baseless conjecture about the end of the world is given the death penalty if that day comes and goes? I'm tired of this idiocy year after year.