The problem for the Saudis is that they are faced with a choice of the present regime in Syria who are Alawis, and becoming more and more accepted as part of the Iran/Iraq Shia religuous grouping. There have been Iranian Fatwahs in recent years stating the Alawis "are" Shia, and so "friends". If they regard themselves as Shia, then by definition they are anti-Saudi (anti-Sunni, anti-Wahabi). The flip side is that if the Syrian regime falls, what will replace it? A bunch of Al-Qaeda nutters - one of whose prime objectives is to remove the al-Saud family control over Mecca and Medina
Better the enemy you know maybe...
Lonewolf
The problem of course is that if the Egyptians were to shut the canal in protest - they would be doing exactly what the Iranians want - cutting the allied Red Sea / Persian Gulf fleets from its main supply route, and also screwing up the economy of Europe.