The issue has come up with the so called Arab Spring. I also cannot imagine, that Israel will be striking Iran's facilities. Such a strike would be too complex to be accomplished with Israels Air Force. Many of the targets are hardened, so that they would require many strikes and bomb damage assessment between the strikes. In order to effectively disintegrate Iran's nuclear capabilities, Israel also would have to take out its counter strike capability, which would be the most complex task.
All this will require thousands of air strikes.
At the same time, Israel might be left without sufficient air defense regarding Syria. The Syrian air force is by far inferior to the IAF, but if too many IAF jets are involved in striking Iran, it might make it feasible for Syria to lead an air strike against Israel.
At the end, only the U.S. has the capability to lead such a strike against Iran and Israel may take part in it, but I don't believe, that Israel can perform this alone neglecting it's deterrence against its direct neighbors.
With its drills Israel is sending a strong Message to Syria and Hezbollah and by the way readies for a potential conflict. I have the impression, that Assad comes closer to loosing his restraint from striking Israel, while the U.S. is withdrawing from Iraq, thus opening a land corridor between Iran and Syria.
Thinking this scenario, the message also could mean: Look Ahmadingdong and you Chamenei: If you intend to strike Israel via Syria, we will be able to hit you really hard at home!