I see no actual atmospheric spectra of any kind. All I see are simulations and models. This is all well and good, but someone ****ed up telling this to the media (or the media did, which is more than possible). Until I see actual spectra taken of Gliese 581d's atmosphere, this is overblown, and I will maintain that the Yahoo article is blatantly false. Those spectra are going to be a long time coming, too, as I recall that the Gliese 581 system does not have any transiting planets on our line of sight.
EDIT:
This is the most recent paper they've posted to the ArXiv, which I think is what these press releases are getting based off of.
It's more simulations. There is not a confirmation of the first habitable exoplanet at all, only that it may lie in the habitable zone for some plausible cases of atmospheric composition.