If Iran doesn't retaliate against US targets then one would hope that's the end of it as far as the US is concerned. Hopefully thats the enrichment programme reset to day zero.
The Ayotallah and his cronies are scumbags, but as we've seen in various other countries in the Arab world, toppling a scumbag usually makes things worse.
I read somewhere last week that the Shah's son wants to be an interim leader if the current regime is toppled. An awful idea IMO, his father's brutality is why the current bunch of nutbags took over when they did.