Thanks very much Tim and thanks to Luck for starting this thread.
Over at
http://www.2012hoax.org , there was an enormous spike in visitors, both unique and those returning, in the days leading up to and including Dec 21st, as can be seen by these stats posted by Bill Hudson:

Many people who were scared by the 2012 claims, will have learned from this epic doomsday failure to think critically and won't be fooled by the scammers and hoaxers so easily again. However, the doomsday nutters never give up and over on Youtube, amongst other things claims are already being made about Comet ISON in November 2013 and linking it to Nibiru, as they did with Comet Elenin last year. They went nuts over Elenin and that one wasn't even visible to the naked eye, but it's possible that ISON could be very bright indeed - maybe even
brighter than the full moon, so if that
does turn out to be the case the nutters will go absolutely ballistic I should think. That said, comets that are thought will be bright often disappoint in the end, so there's certainly no guarantee that it will be.
In my experience most of those making doomsday claims are either scammers who do it for money, or (especially on Youtube,) trolls/hoaxers who do it for a laugh ...