James M. Dorsey, "Soccer Fans Play Key Role in Egyptian Protests" (readers of this blog will not be surprised, as this is a fairly consistent topic in writing about the sport and politics).
The Football Scholars Forum posted a link to that story and to this BBC interview with David Goldblatt (of The Ball is Round): The Secret Policeman's Football.
In 2007, Tom Dunmore posted a series of articles on Pitch Invasion about "Ultras" - a genre of football fan club, characterized by intense organization, often somewhat militaristic structures and overtly political ideologies. The series includes this photo essay from one of the founders of Egypt's first Ultras group - Ultras Ahlawy.
An interesting 2009 Al Jazeera article about football and nationalism, The Politics of Sporting Rivalry, written by the author of The Angry Arab News Service.
I will post more articles when I find them.
There are lots of videos of the Ultras Ahlawy on youtube, highlighting their actions at matches. I've included a few turned up by a simple search.
The USSF announced its cancellation of the men's friendly match in Egypt (scheduled for Feb 9) in a very neutral press release.