Anonymous announces a November 5th 2013 Million Mask March in Washington D.C. and major cities throughout the United States and the rest of the world. More here on CNN.
There's a Million Mask March blog here, Facebook page here, and website here with a map of locations here.
As for video announcements, searching youtube, I found tens of thousands already posted. Here are a random few (one and two and three), with the National Mall reportedly the gathering place for those heading to the U.S. capitol.
Photo credit/top, Wikipedia, photographer: Jonathan Mauer , Guy Fawkes mask at Occupy Protest in Buenos Aires Argentina October 15, 2011.