It's no secret that Israel and it's supporters are nervous about the prospect of a democratic Middle East. The new situation dramatically reduces their ability to pursue an expansionist agenda in the West Bank. Even if Egypt is ruled by secular democratic forces, the new governments must take into account public sentiment towards the Israeli Palestinian conflict. The same is true for Jordan, even if it's government survives.
I suspect that the Netanyahu government will soon find itself in an untenable position regarding settlements, and may have to limit growth because of external pressures. If not, there may be serious economic and security consequences.
I suspect that the Gaza blockade will die a swift death, with barely a peep out of the Israeli government. Can they risk an open conflict with Egypt over Gaza? The Palestinian pursuit of UN recognized statehood is now almost a certainty. How can Obama oppose it after publicly supporting the Egyptian(and Tunisian) struggle for democracy and self determination?
The Zionist fantasy of a "greater Israel" is now effectively dead. It died in Tahrir Squre this afternoon. What the Palestians can salvage from this will not be much, but it will be better than nothing at least.