From today's Haaretz editorial:
The time when Israel could enjoy peaceful relations with Egypt while freezing progress with the Palestinians and building settlements is over. It's also possible that we're approaching the end of the era in which we enjoy the United States' blind support for a government that consistently works against the American position on settlements and publicly criticizes its president. But the choice between welcome initiative and cursed inaction is still in Israel's hands.
Avigdor Lieberman put out a marker yesterday that Egyptians will take not of, ruling out any changes to the Egypt-Israel peace treaty that has become a major Egyptian demand with cross-partisan support. But it's never been clear in the current Israeli administration who Lieberman speaks for; foreign and national security policy is in the hands of the Netanyahu-Barak tandem, and Lieberman is routinely ignored. Furthermore, there is a line of thinking among some Israeli officials that renegotiating the peace treaty would amount to a positive commitment by Morsi / the MB to the treaty itself — i.e. more of a buy-in then there currently is despite their repeated statements that the treaty would be respected. One might also expect the Israelis to make it a condition of renegotiating the treaty that Morsi sign it personally — because so far it appears he has no intention of meeting an Israeli official at all (indeed, there might be some strenuous avoiding of even an accidental meeting by the Morsi team at this week's UN summit).