According to this piece in the WaPo, the latest Al Qaeda attacks in Riyadh will backfire. I both suspect and hope that he's right.

Al Qaeda's true motives have been revealed to Saudi citizens. It is not a desire to free the kingdom from "occupying" forces (U.S. troops were already on the way out) but a barbaric and bloody hatred of the modern world. This is a vision almost no Saudi supports. The bombings should also lead Americans and Saudis to focus on their mutual interests, the most important of which is defeating global terrorism.

If the article is correct, it also indicates a high level of desperation on the part of the terrorists:

According to Saudi intelligence sources, nine of the bombers had narrowly escaped a recent government raid. With their names in the Saudi press and a wide-ranging manhunt underway, their time was running out. In fact, a captured high-ranking member of their cell revealed that increasing pressure from Saudi and Western intelligence agencies led the group to rush its plans, resulting in a desperate, scattershot attack that injured their cause.

Also, for what it's worth, Fareed Zakaria agrees.