Nathan Brown outlines possibilities:
The danger of indefinite military rule in Egypt is small. While pundits have often proclaimed the military to be the real political power in Egypt since 1952, in fact the political role for the military has been restricted for a generation. And there is no sign that the junta wants to change that for long. It is order, not power that they seem to seek.
When the generals suspended the constitution, most opposition elements saw that as a positive step because it made possible far-reaching change, and I think that was a correct political judgment. (The suspension led to odd headlines in international press referring to Egypt as now being under martial law. But Egypt has been under martial law with only brief interruptions since 1939. It was not the generals who placed Egypt under martial law; that step was taken by King Faruq.)