A lengthy but definitely worthwhile read.
http://news.morningstar.com/articlenet/article.aspx?id=353648
Distinguishing between near-term price performance and long-term opportunity.
Mounting concerns about energy independence, emissions reductions, and affordable power have heightened the demand for energy alternatives.
While not all available options are economically viable, recent times
have seen natural gas touted as the "fuel of the future" in the United
States. The environmentally conscious look to natural gas as a "bridge
fuel," predicting that it will replace its carbon-intense cousins, coal
and oil, until technological advances allow carbon-neutral energy
sources to supersede fossil fuels altogether.