As Computer Forensics Experts, we have to view some seriously harrowing material.  There are few things as difficult to see as the video of James Foley being beheaded.  Our thoughts are with his family, friends and colleagues.  
We are not involved in the analysis of the video, but were pleased to be able to consult with Tom Cheshire of Sky News, and give him some insight as to how we use computer forensics techniques in the  video analysis of videos to assist with victim / perpetrator indetification. His article: "How Forensics Experts Will Analyse Beheading Clip" is a useful summary on how the experts appointed to the investigation will analyse the footage to identify the perpotrator and his location.  We were glad to be able to assist.