I believe that the opening shots of the Social War will be fired sometime during the summer of 2009. However, it is not quite time for the breakup of the U.S.
I think you are correct, and it will begin in California. That state is the best candidate for an actual shooting war to break out. The drug gangs and violence from Mexico are almost at the breaking point of civilized society right now.
In parts of Mexico proper, lawlessness has already begun. General McCaffrey has already warned us.
http://www.mccaffreyassociates.com/pdfs/Mexico_AAR_-_December_2008.pdf