Penn and Teller did a Bullshit on this and brought up a great idea...
Open a loan company quickly, and offer any believers $2000 for their home, which only changes hands on 22 December 2012, you get a pile of cash to spend on drugs and hookers to enjoy before we're wiped out, and if by some miraculous chance it doesn't happen, we get a bunch of properties to sell on at about 99% profit and you get to find a dumpster to live in for believing in fuckwitted stuff.
After all, if it's real, does it matter that you lost a pile of sets of $2000? money won't exist, and we'll all be raiding soda machines for bottlecaps.