CERN has released an interim report on the 9/19 incident:
http://press.web.cern.ch/press/PressReleases/Releases2008/PR14.08E.html
Interesting reading, especially the full report posted here:
https://edms.cern.ch/file/973073/1/Report_on_080919_incident_at_LHC__2_.pdf
It includes a detailed primer on the LHC configuration and layout, which is essential for understanding where the problem started (an electrical bus between two magnets) and how it spread to the cryogenic system.