The Saudis (and most Gulf states) are as afraid of Al Qaeda and militant Islam as the West.
The enemy of my enemy is my friend.
That is the type of idiotic simplistic thinking which spawned Al Qaeda and the Taliban in the first place. Remember when we supported them against the Soviets in Afghanistan?
The enemy of our enemies is often, not a friend, but an even worse enemy. When speaking of Muslims they are never our friends no matter who they are battling. Bush and the US state department are too stupid to learn this simple lesson however. They are traitors.
An ally of convenience perhaps, but not a friend. And an alliance that should be examined.
Good relations are important, like China the Saudis are important trading partners.
Like the Soviets, and to a lesser extent China of today, the Saudis, along with Iran and Egypt, are exporters of a virulently anti-American ideology which we are confronting violently in various regions, as well as within the US. That needs to be taken into consideration when assessing the relationship.
Given the 1991/2003 experiences with the kingdom I think it's fair to say the Kingdom will welcome our blood, they'll even use their own treasure, when they're threatened. As an ally, unlike Kuwait for example, they'll be no help militarily.
This doesn't mean we don't trade with them, don't have cordial relations, but imo it does mean we don't supply the Saudis, or Egypt, with multi billion dollar packages of advanced arem that are unlikely to advance our interests. Egypt has no land enemies in the region, other than the one to the NE their military trains to attack. The idea that the Saudi's will confront Iran for us militarily is naive.