Yglesias and Krugman have positive things to say about Obama's decision to have the EPA regulate carbon emissions. Both essentially make the same point, which is that Obama is finally starting to see that he's not going to be able to reason with the Republicans. Here's Yglesias:

Once upon a time, of course, the White House had a fairly ambitious second term agenda...

Indeed, the "fiscal cliff" deal with congressional Republicans that raised less revenue than progressives wanted and less than it seemed like Obama could get by playing hardball was justified in part in the name of that agenda. The theory was that the president needed to clear the decks of the tax issue in order to make room for action on comprehensive immigration reform, gun safety regulation, a new surface transportation bill, and maybe even an overhaul of K-12 education.

But a fairly weak gun bill hashed out by Senators Joe Manchin (D-WV) and Pat Toomey (R-PA) was filibustered to death in the Senate. An immigration bill that did manage to pass the Senate is languishing in the House where John Boehner won't give it a vote.

I agree with all of that and i'm glad that the EPA will be taking this action. But it's worth noting (again) that this is basically required by law after a 2006 Supreme Court case. Both Bush and Obama dragged their feet on this, but it's not like Obama is suddenly and unilaterally making this decision. This gets surprisingly little mention, and when it does it's mainly to deflect (absurd) charges of fascism, but it was covered recently in a TPM Cafe piece.