[DeilMikina]

The Aztecs also thought the world would end every 52 years unless the Gods got an enormous supply of fresh human hearts to keep their strength up.

So, none of the above.

[gernica]

The wheel thing probably had to do with a lack of animals suitable for cart-pulling, though given their attitude towards human life they might have just used teams of slaves.

I'm not sure about having more credibility than Scientologists WRT the world ending. Certainly they have more than the Jehovah's Witnesses, who've predicted the apocalypse roughly fifty times IIRC.

[stunnyravytal]

OK, there is the end of a 5000+ years cycles of one of the most complex and original calendars, and it is interesting to live that day (just as it was cool to live in the year 2000).
Everything else is complete fabrication and idiocy, assuming a coinciding "real world" scientific disaster "just because". And since nothing seems to really indicate that there will be disaster, let's cling to far-fetched theories like polar shifting, CERN and other worm holes...
I take the disaster in 3100BC was the Great Deluge...