Around 5:08 of the video [youtube.com...] Matt Cutts said that the new Panda would look for those "additional authority signals" that would soften the effects of Panda.
What authority signals could have been overlooked. Any ideas of what those might have been?
[ Although I don't know the process, it should be noted that the rollout appears to have commenced 3-4 days ago, and according to MC should continue for approx. 10 days in total].