The US Geological Service has posted a feature on their website that evaluates the likelihood of doomsday occurring on December 21st. Based on the Mayan Calendar, December 21, 2012 is the last day on the Mayan Calendar. To address concerns that an end-of-days has been foretold over 5-thousand years ago, the USGS has thrown in their two cents.

From the USGS Website:

“Based on interpretations of the ancient Mayan calendar, some people are predicting the world will end on December 21, 2012,  Others believe that instead of doomsday and destruction, the day will mark a new era for humanity and will be a time for celebration.

Such beliefs aside, what we know with certainty is that Earth has a tremendous capacity to generate natural disasters on any day of any year. For this reason, U.S. Geological Survey (USGS) scientists continue to look for ways to better forecast a wide range of natural hazards and protect our communities.”

The feature then describes what predictive capabilities the USGS is hoping to improve, including earthquake forecasting, volcanic unrest, landslides, wildfires, hurricanes and severe storms.
Their verdict on whether the apocalypse begins on Friday? Acording to the website, people should be prepared :

The question to consider on December 21, 2012, and every day is: Have I done everything I can to ensure that my family and I are prepared, should a disaster strike? This includes preparing and practicing your emergency plan and building a disaster supplies kit with food, water and basic needs. Natural disasters will continue to occur, on any given day, but a more informed scientific understanding can lead to better preparedness and safer communities.