Big (and bad) news.
* Saudi Arabian oil production is now in decline.
* The decline rate during the first year is very high (8%), akin to decline rates in other places developed with modern horizontal drilling techniques such as the North Sea.
* Declines are rather unlikely to be arrested, and may well accelerate.
* Matt Simmons appears to be right in Twilight in the Desert, but the warning did not come until after declines had actually begun.
I suggest that this is likely to place severe political strains on Saudi Arabia within a year or two at most.