So I don't think the world will end in 2012 any more than it ended in 2011.
That is no reason not to play along.
Every holiday from now (or from Dec 21, 2011,) be sure to holler (all the time) that "This is the last [INSERT HOLIDAY] ever! Party hard and enjoy it, because you won't get another one!
In the future, any time there's an end of the world prediction, be sure to do the same. Because people like being told to party hard.
Ok, that's pretty much it, but remember, enjoy your new years, because IT'S THE LAST ONE EVER!