There is a revealing video interview (4 minutes) at:
http://www.globalpublicmedia.com/#200402simmons where Simmons elaborates on the state of Saudi Oil and says he beleives they are poised for decline.

Simmons says ìWe could be on the verge of seeing a collapse of thirty or forty percent of [Saudi] production in the imminent future, and imminent means sometime in the next three to five years ñ but it could even be tomorrow.î