Syria's military forces are far from capable of mounting any such sort of operation either now or in the near furture.
Since the fall of the Soviet Union, Syria's forces have been in near constant decline, despite several attempts to improve equipment, organisation and training.
Unfortunately for Damascus, she has little in the way of hard currency to support new procurement. Fairly significant attempts to improve Air Defence Forces with new MANPADS, radars and SA-18s have been made however, and Anti-Tank capabilities have been improved with large quantities of AT-11 being purchased. It should be noted that in both of the latter cases, Westerm Intelligence has speculated that these weapons may end up in the hands of Hezbollah and their like. Western European companies have also aided in the modernisation of under several hundred T-72 MBTs.
Another major problem for Syria's armed forces is that POL imports are at an all time low - the IDF itself 12 months ago stated the Syrian Air Force was operating at minimum flight hours due to severe fuel limitations.
Their training and exercise schedule is even more limited than it was before. Even units that were once considered fairly well trained like the Republican Guard Division and the Special Forces, are now a shadow of their former self.
All in all, I think Syria would be far from eager to march back into the Lebanon or the Golan. But then again, stranger things have happened...