Here's the relevant quote from his interview with Scott Pelley on 60 Minutes last night:
Woodward: This is very sensitive and very top secret, but there are secret operational capabilities that have been developed by the military to locate, target, and kill leaders [in Iraq].
Pelley: What is this? Some kind of surveillance, some kind of targeted way of taking out just the ... leadership?
Woodward: ... It is the stuff of which military novels are written.
Pelley: Do you mean to say that this special capability is such an advance in military technique and technology that it reminds you of the advent of the tank and the airplane?
Woodward: Yeah.
Quoted from the 60 Minutes video starting at 7 minutes 55 seconds: http://www.cbsnews.com/stories/2008/09/04/60minutes/main4415771.shtml
I'd like to ask the readers here what they think this groundbreaking technology might be? I'll start off with these two guesses which might be feasible today:
(1) facial recognition by satellite or high-flying aircraft
(2) wholesale tracking and transcription of all cell phone calls