What does the embassy crisis tell us about Egypt?

The invasion of Israel''s embassy in Cairo by a violent mob has raised some disturbing questions that touch on both short-term and long-term outlooks for the future of relations with Egypt.  
 * Why did Egypt''s caretaker leader, Field Marshal Hussein Tantawi, head of the Supreme Council of Armed Forces, evade urgent phone calls from Israel''s prime minister and defense minister, thereby endangering the lives of Israelis trapped in the besieged embassy?
* Did Tantawi''s refusal to come to the phone signal a new approach to Israel by Egypt''s military chiefs?
* Even if the Egyptian military has the will to prevent a further deterioration with Israel, does it have the ability to enforce its will in an Egypt that is increasingly characterized by anarchy and instablity? Will the desert dunes of Sinai continue to be a lawless haven for jihadis despite moves by Cairo to seize control of the area?
* Another question that seems appropriate to ask: Why did Israel leave personnel in the Cairo embassy despite the fact that it had become the scene of regular, violent disturbances, and a place that had clearly become unsafe?
* Beyond these questions, the simmering hatred for Israel on display in Egypt seems to indicate the shortcomings of having peace with a regime but not with its people. For the duration of the peace treaty, the Egyptian media has been filled with anti-Semitic and anti-Israel content that has all but ensured that many Egyptians would continue to view their northern neighbor with great hostility. 
Egypt is scheduled to hold parliamentary elections in October.
The Muslim Brotherhood has for years been working to create a base of support among poor Egyptians by providing social assistance intermixed with Islamist ideology, as part its overall goal of setting up a hardline state. 
Should the Brotherhood do well in the elections, it would not be difficult to envisage the rise of a new Islamist Sunni bloc consisting of Egypt, Turkey and the Hamas regime in Gaza. Hamas openly declares itself to be the Palestinian branch of the Muslim Brotherhood. 
Many believe that Shi''ite Iran would feel threatened by such a bloc, viewing it as a threat to its self-declared leadership of the radical Middle Eastern axis.