me too
i walked in today as well for my wife's pp stamping at the SFO center. it was clearly written that only infopass appts will be accepted after October.
as a result, and as you might imagine, more people want to get their stamping done before they go thru infopass and so the lines are much longer.
i had done my stamping in july and the line was shorter then even when i arrived at about the same time (5:45am).
just an observation, if it helps someone - good.
cheers