One reason that coal-fired power plants are having a good run in 2013 is rising natural gas prices, but a second factor boosting coal generation is the continuing drop in output from nuclear plants. In the first two months of 2013, nuclear output fell 2.5% compared to the same period in 2012 and 3.5% from 2011 levels.
http://www.eia.gov/totalenergy/data/monthly/pdf/mer.pdf at section 8.
In January and February 2013, nuclear plants cumulatively generated 132.8 billion kilowatt-hours and operated at a 92.3% capacity factor. Those numbers dropped from 137.5 billion kilowatt-hours and a 96% capacity factor in 2011.
The drop in production reflects continuing plant struggles in California and Florida but do not include the recent retirement of a nuclear plant in Wisconsin. In short, the full 2013 is shaping up to be a not good one for the nation's nuclear fleet.