The Internet seems abuzz with the Maya calendar and 2012, but it's rare for that buzz to include anything factual about the Maya. I contemplated a long ramble, but decided to direct you to David Stuart's succinct explanation here.
For anyone boarding themselves up on the 21st, the correlation between our calendar and the Maya calendar is still a debated issue. The PARI Journal just published a paper that advocates for a correlation that would push the much-anticipated date to Christmas Eve (link). That paper's kind of technical, so here's a more general explanation of correlations and the complications of the Gregorian Calendar, which favors the 584285 correlation (link).
However much I'm not worried about the world ending, I am excited to see a b'aktun complete. I will not be alive for the next one in 2407. So I'll be celebrating how we celebrate most things around here: treats and boardgames.
See you all next year!
ETA: And, of course, as soon as I post this, David Stuart's blog pops up
with an accessible-yet-detailed explanation of the breadth of the Maya