Israel is either being 'safe rather than sorry' or sees the writing on the wall. If from a successful revolution, the Fundamental Islamic side takes power (as apposed to the more pro western side), Egypt's relationship with Israel would take a turn for the worst in a hurry.
"Israel repatriated families of its diplomats in Egypt on Saturday in response to the unprecedented street protests in the Arab state with which it has a 1979 peace deal.
"A special aircraft brought back to Israel on Saturday the families of diplomats and other official envoys, as well as about 40 Israelis on private visits to Cairo who wished to leave," said foreign ministry spokesman Yigal Palmor.
The Israeli ambassador to Egypt remains in the country."