Why is it that in certain circles there is so much emphasis placed on the Mayan calendar? So one era of said calendar comes to a close in 2012 and a new one begins. So what? What is so damned significant about their calendar?! I'd really love to know. Why theirs and not, say, the Chinese? Or the Jewish? Or etc.?

Good question.

The Mayan calendar ends when the sun conjuncts with the Tree of Life (the galactic plane and the ecliptic). This signals the end of an era (but not necessarilty the world).

However, the Hidu calendar says the avatar of Krishna will arrive in 2003, preceeded by many calamaties and disasters and "strange happenings," indicating the beginning of the Age of Dharma (Righteousness).

Bede the Venerable calculated the end of the world in 2058, 6000 years after the Creation (based on the birth of Jesus in 3942 AC).

Sufi Muslims look for the end in 2076 (their year 1500).

The Jewish calendar marks 2240 as the end, 6000 years after the Creation by their calculations.

I think so much signifigance is given the Mayan calendar because it makes some amazingly accurate astronomical predictions. They seemed to understand, f'rinstance, the concept of precession and accounted for it in their calendar. Thus, the end of the era on December 21, 2012... the winter solstice.

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