It's not just Grand Ayatollah Hossein-Ali Montazeri rebuking Mahmoud Ahmadinejad, it seems. This week, past Iranian president Hashemi Rafsanjani criticized Ahmadinejad's economic policy, and apparently Iranian newspapers are printing critical editorials about his economic practices and his bellicose international stance. As this BBC article points out, this almost certainly means that those otherwise in power in Iran are starting to think of Ahmadinejad as a liability. They may not want him out of power, but they certainly want him to behave.
Again, the parallels with our executive are clear, even if "those in power" has a different meaning in the States than it does in Iran.