User blog comment:CenturyKiller/Earth Like Planet Found & Any News on ME2 or 3?/@comment-217683-20100930233552/@comment-899316-20101001000130

Indeed, and thus I said potentially habitable. They could be, but we don't really know, and as accuracy is important in these matters, we default to a verdict of "uninhabitable". Too hot or too cold is too distinct a possibility with the other two planets. Not so with 581g, however. We appear to have confirmed it's habitability by at least some form of life.