The EPA announced some new regulations called the Clean Air Interstate Rule, which affects 28 eastern states. The idea is to reduce NOx and (eventually) SO_2 emissions over the next 10 years. Here's the NYTimes.com story: The New York Times > E.P.A. Announces New Emissions Regulations for Eastern U.S. by Michael Janofsky.
The "story" is that the crappy Clear Skies Act can't get through Congress, so the EPA is moving forward without Congressional input. Everyone is pretty much in favor of the Clean Air Interstate Rule, but most environmentalists are very much against the Clear Skies Act. Why? Well, the Interstate Rule sits on top of all the other legislation we have, namely the Clean Air Act. The Clear Skies Act would strip away some important aspects of the Clean Air Act, and would also ignore carbon dioxide (and methane too, I think) emissions. So while the Interstate Rule is a small step forward, the Clear Skies Act would be a big step to the side, letting power plants run right by with their dirty ways. Bad.
The Interstate Rule will help states who are victimized by their upwind neighbors. I'm not so sure if it includes by-products though. For example, if Cleveland produces a lot of NOx that blows toward Pittsburgh (this is hypothetical, I don't know about residence times and mean wind there) but it becomes ozone by the time it gets there, will Pittsburgh have an actionable position? They should, since it is the NOx from across the border that is leading to respiratory problems of Pennsylvanians. This does happen within southern California. Traffic on the westside produces lots of NOx, which blows inland toward San Bernardino and Riverside and Pasadena etc, and chemistry happens along the way. Of course, Riverside can't sue Long Beach over this, but Pennsylvania might be able to sue Ohio.
As for the Clear Skies Act, I have to add to the dissent. It isn't enough, and it gets rid of some good regulations on power plant upgrades. If anything, we should amend the Clean Air Act to make it stronger and include greenhouse gas emissions. Why will the federal government not pay attention to greenhouse gases? It makes no sense!!