It's a new blog called RealClimate.
Many scientists participate in efforts to educate the public and to rebut or debunk rather fanciful claims or outright mis-representations by writing in popular magazines such as EOS and New Scientist or in the Comments section of journals. However, this takes time to put together, and by the time it's out, mainstream attention has often moved elsewhere. Since these rebuttals appear in the peer-reviewed literature, these efforts (in the long run) are useful. However, a faster response would sometimes be helpful in ensuring that the context of breaking stories is more widely distributed at the time.
Journalists with deadlines and scant knowledge of the field quite often do not know where to go for this context on papers that are being pushed by some of the partisan think-tanks or other interested parties. This can lead to some quite mainstream outlets inadvertently publishing some very dubious and misleading ideas.
RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists. We aim to provide a quick response to developing stories and provide the context sometimes missing in mainstream commentary.
A December 18 entry is called "Fox News gets it wrong".