I just read the same article in the NY Times (by Jeff Gerth).  You left out the most amusing part, where Saleri from Saudi Aramco replies to Price "that the basis for the higher oil figures was a global study in 2000 by the United States Geological Survey estimating Saudi Arabia's undiscovered resources at 87 billion barrels," and Price procedes to ridicule the 2000 USGS estimate.

It is my understanding that the USGS assumptions about global reserves were based on an argument the better technology boosted recovery in Texas fields from roughly 25% in in 1970 to 50% in 1995, and the application of the same technology to the rest of the world would similarly boost global reserves.  This argument always seemed somewhat flaky to me; clearly the effectiveness of horizontal drilling and water/gas injection won't yeild the same results in differing geology.  Also the USGS study seemed to imply that technology would continue to inprove recovery by similar amounts in the future, which is also a dubious argument - surely diminishing returns will stall out ultimate recovery far short of 100%.

In any case, we will see if this "leak" to the press will induce the Saudis to be more forthcoming about the source of these enourmous new reserves that so many cornucopians are counting on.