A lot of good points have being written so far.
What must be going on now is a frantic search of the CVR and DFDR by the Egyptian authorities to get there first. Why? Simply so they can tell the world whatever official version they already have.
A good model of how the Egyptians will deal with this tragedy is the way they dealt with their 767 accident. Even though the NTSB proved black on white that El Batouti(the F/O) was directly responsible for the crash, the Egyptians refused to see the truth and continued their propaganda.
Moral of the story: You cannot, ever, trust whatever Arab officials say. Period!The fact that the French DGAC is getting involved is not going to change anything. Actually they might turn it into an anti American thing by "proving" that the 737 has a history of problems and that airlines should buy Airbus.