After 2012 comes and goes...
... I wonder what they/someone will set as the next date for the 'end of the world.'
Seems like that we get a new set of dates for the apocalypse every ten years or so.
Funnier still, "If you guess at the answer often enough... sooner or later you will be correct!"
My guess is that if we haven't already pushed the environment past its 'tipping point of no return' we'll eventually destroy the atmosphere enough to make the damage irreverseable... and life here will grind to a halt with a long-slow whimper over many years.
No supernatural involvement or catastrophic event is even required. We're doing a fine job of wrecking the planet without any dramatic assistance.