SFO's new international terminal is scheduled to open on September 26, 2000. The airport has promised that the "passengers only" restriction will not be implemnted in the new building, therefore if you are arriving at the new terminal you might be able to go back up to departures after you clear customs and get to the lounge.

Somewhat odd for the airport to have claimed forever that the restriction was for security purposes, but now lift it for commercial reasons (shops and restaurants past security).