Al Qaeda's track record seems to indicate that recon takes place early (obviously), which would work out to two or more years in advance of an attack. There are probably initial reconaissance trips made by agents who will not participate in the attack, followed by intelligence gathering by the perpetrators (a la 9/11). If this is the case, then these re-con agents captured in Pakistan have already been utilized on the flow chart toward the event. with cells already being contacted here, it appears to me that baton has already been passed.
If Al Qaeda is as compartmentalized as we believe it to be, then it's unlikely the planned perpetrators have "touched" the arrested lackeys in Pakistan... whether or not there is a "failsafe" point at which the operation goes forward regardless of other events, we don't know...
Possible incident of interest in San Diego...but no real follow up details here yet:
9:46AM - THE RAMP REMAINS CLOSED
9:44AM - AT PRESENT, SD FIRE DEPT S "EXPLOSIVE ORDINANCE DISPOSAL" (EOD) IS ON SCENE AND WILL HANDLE
8:40AM - SDPD IS ENROUTE W/ A BOMB SNIFFING DOG
8:40AM - CHP ON SCENE - THE CLAIREMONT MESA OFFRAMP FROM NB 15 HAS BEEN CLOSED AND A SIG ALERT ISSUED
8:39AM - THE CALLLER WOULD LIKE AN OFFICER TO RESPOND AND ENSURE THAT THE OFBECT IS NOT A (POSSIBLE) PIPE BOMB
8:37AM - PER 911, THERE IS AN OBJECT WHICH APPEARS TO BE A SMALL PIPE LOCATED AT THE TOP OF THE OFFRAMP
8:35AM - CAD #170 - SUSPICIOUS ACTIVITY; NB 15 ON THE CLAIREMONT MESA BLVD OFFRAMP @ 7:39AM