The gas versus coal competition in the power markets was never more intense than in 2012. The result of the intense competition is substantial changes in the generation market shares of both fuels that meant gas had its highest market share and coal its lowest market share in decades.
Gas generated 30.3% of America's electricity, a sharp increase compared to the 12% in 1990 or 16% in 2000. Coal provided 37.6% of the nation's power, sharp declines from more than 50% 15 years ago, 48% in 2008, and 43% in 2011. http://www.eia.gov/forecasts/steo/pdf/steo_full.pdf. Last year was an extraordinary one, indeed.
The competition between gas and coal continues, with 2013 likely to see coal reclaiming some of its lost market share, because coal prices are down and natural gas prices are rising from their incredibly low 2012 level.