NY to cap and trade greenhouse gas.

NY State to lead 9 other states to reduce greenhouse gas emissions.
From Here:

Additional States are NJ, NH, Connecticut, Delaware, Maine, Maryland, Massachusetts, Rhode Island and Vermont.

Spitzer went on to say:

Here is the NYT article.

They link to the actual Initiative: 10-state Regional Greenhouse Gas Initiative

It includes a PDF of the Memorandum of Understanding.

From a Press Release PDF a better summary:

I think it is a monumental initiative that will hopefully lead the way to a cleaner US and a better planet. I am very happy this is going through and I hope and expect California will follow suit or better soon.