The Great 2012 Scare: Article by E. C. Krupp in November 2009 Sky and Telescope (page 22). The world won't end on December 21, 2012, but for those who might ask, here is what to tell them.
2012 -- A Scientific Reality Check: Blog entry by Don Yeomans debunking many of the 2012 "predictions" of doom-and-gloom. Contains some nice links to other information on the "silliness" surrounding 2012.
Betelgeuse Supernova in 2012?: Blog post by the "Bad Astronomer" Phil Plait on this nonsensical issue that went viral in January 2011. No, folks, astronomers have absolutely no evidence to suggest that Betelgeuse will go supernova in 2012.