Israel has lost the bigger battle. Unfortunately this will get worse before it will get better. Why wouldn't Syria take it back? Now is the time.
The world won't allow Israel to do anything.
The Golan Heights is among the most commanding strategic positions in the world. It is fortified in depth as a 3-D battlespace, and any army that sought to take it would have to make a long approach in plain sight of IDF defenders. Deep air interdiction by the Israeli Air Force would decimate the Syrian columns before they even drew close enough to fire their weapons, and they would be finished off by IAF close air support and IDF artillery and tank fire. I cannot imagine any force in the world that would want to attack the Golan Heights from the east -- into the full fury of an IDF/IAF fighting for its survival. On the other hand, a timid appeaser like Ehud Olmert might just give it to the Syrians in exchange for promises...