I think chances of an Israeli attack on Iran remain very high. Netanyahu has gotten away with everything so far so he probably thinks he can get away with attacking Iran as well, even if it may not have the desired results of dismantling Iran nuke program. His assessment that the US would still protect Israel from Iranian retaliation are correct, the last two years have cleared up any doubts that AIPAC/ADL effectively own the US congress and executive.
Another Israel-Iran tit for tat would effectively scuttle the current negotiations between Iran and international community for at least another 6 months too.