Found at a new website that is either run by Dr. Carl Johan Calleman or just supports/sells his ideas:

Jeremy wrote: "So you're saying mankind is going to become enlightened in 2012 and there will be no more suffering, starvation, sickness, lonliness, evil and war?" Reply: Correct. Note however, we concur with Calleman's finding that the ending of the calendar is actually October 28, 2011. 2012 will certainly be a time period of adjustment to these sweeping changes.

I figure the date being 1 year ahead of the most common understanding will allow his followers to take magic mushrooms for a year and pretend that they have evolved to a higher level of light-being something... before the real end comes along.

Source: mayan-calendar-code.com