The SOCOM official website writes:
"Seven days til the Public Beta kicks off.
What's your plan? Taking off work? Did you quit your job? Call up a babysitter? Prepare a fort in the front room near your PS3? Let the family know that you're gonna be in-country for a while and to just leave dinner nearby?
I've got some "down to the wire" beta info for you. I checked with the team and the beta is going to be available for download on Monday, September 1st"