This article is a bit long, but well researched and written.  The article title really doesn't reflect the thrust of the article, but towards the end, it does express concerns by one or two "experts" who worry that the rush to NG because of its commodity price and efficiency will backfire in the long run as NG prices increase.  Of course, the article pretty clearly lays out exactly why there is a rush to NG.

GE's New Gas Turbines Are State of the Art, But Are We Getting Too Cozy With the Fuel?

Are We Getting Too Cosy with Natural Gas - Jared Anderson, The EC