Income per capita has roughly fallen by 2/3rds since 1974 in Saudi Arabia (population has tripled, the real price of oil is no higher, there hasn't been enough other industry come in to fill the gap).

Saudi Arabia is also dependent on 'shadow water' (the term used to mean the water imported as part of food and other products)- -it doesn't have enough of its own resources.

The country is on the edge of very serious political and social trouble.  The combination of widespread religious radicalism, a corrupt ruling class, the absence of any meaningful democracy, and poor prospects for the huge majority of the population under  21 is a lethal cocktail-- precisely what led to Algeria's civil war for example.

Right now, the current high price of oil (and high production) and the ruthlessness of the state security apparatus keeps the lid on.  But there is no question the Royal Family has been shocked by the various terrorist attacks, and the incompetence of the Security Forces at defeating them. The security forces themselves are rumoured to be riddled with Islamicist sympathisers.

Whilst Abdhullah remains alive and in power, I don't expect change.  He is seen as an honest man, and not personally corrupt.  When some of his cousins get to power, the situation may be very different.

Osama bin Ladin may yet see the day when he is welcomed in his homeland as a hero.