There has been a lot news and thought recently about the changing role of natural gas in the US. This has been generated by the advent of two new technologies (fracking and horizontal drilling) that have created access to vast new supplies that were previously thought to be too expensive to extract.
There are legitimate concerns over these developments, as well as great opportunity. I have been researching the issue. Some of my thoughts were published on Xconomy. You can find the article here.