Adam B (Adam Bonin) of http://throwingthings.blogspot.com/ reports in DailyKos that the FEC has ruled that DailyKos did not fail to register as a political committee, because according to the FEC:

“Like traditional media outlets such as newspapers and magazines,
DailyKos has a publisher, Moulitsas, who appears to retain editorial
control over the content of the site, and a list of contributing
editors, who along with Moulitsas appear to be “front page posters” and
draft stories. Further, registered users of DailyKos may post
responsive comments, which are similar to letters to the editors in
traditional media outlets.”