The administration also spoke to Egyptian officials about taking part but Egypt — the leading military power of the Arab world — was concerned that air strikes could endanger some million Egyptians who live in Libya. In addition, protesters only last month toppled the 30-year regime of President Hosni Mubarak and Egypt’s transitional military government remains fragile.
It makes sense that Egypt wouldn't want to take the risk with its air force, for this type of action at risk civilians are a liability. However, if ground forces become a question then Egypt's concerns may change, subject to internal risk. I believe they would be particularly likely to intervene on the ground if Qaddafi attempts a blitz and it looks like a massacre may take place. An insecure regime like Egypt's can't afford this kind of foreign policy crisis this early in the transition process. Expect Egypt's stance to change very rapidly, and unpredictably, as circumstances develop.
Wish I read Arabic so I could read what their papers are saying.