I think Syria already has got the message. Yesterday afternoon/evening when Israel bombed the crossing between Lebanon and Syria, Syria was very quick to tell the world that the attack had NOT taken place on Syrian territory.
Reading between the lines, it seems to say we don't want anything to do with this. Probably at the moment this is a Hezbollah/Hamas/Iran affair. When/if Israel directs heavy attacks on the Bekaa valley things may change, but at the moment it looks like the Syrians want to stay well outside this conflict.
that's going to be tough to do if the IDF goes into Southern Lebanon and really tough to do if they go into the Bekka Valley. I can see 2 scenarios where the IDF would initate contact with Damascus. 1) If there is a missile attack on TelAviv that inflicts casualties 2) IDF feels it necessary to protect its flank during an invasion of lebanon
Syria does and says nothing without approval from Teheran. Knock out Iran and there's little to worry about from Damascus. Ahmadinejad has already said he wants to annihilate Israel. That's a good enough reason right there, and they'd be doing all of us a big favor.