Is the Iranian regime Sistani-able?

Those who doubt the force or staying power of Iran's Green movement often characterize the movement as essentially leaderless and unfocused in its goals. It's true that putative leaders Mousavi, Karroubi and Khatami are presently focusing on reform platforms; they condemn violence and assert that they want to work within the Constitution of the Islamic Republic.  As the regime and hardline establishment figures repeatedly retreat into recalcitrance, arresting and terrorizing demonstrators, intimidating the reformist leaders, calling for executions of demonstrators and sometimes death sentences for the leaders, it's hard to imagine the old establishment reformists finding a path toward meaningful compromise with a regime that has (as they sometimes themselves assert) has lost legitimacy. And it's true that there is no high profile leader calling for a full-scale regime change - which would be impossible from within the country.

At World Politics Review, Masoud Shafaee suggests a possible source of galvanizing leadership for those seeking change in Iran.  In an article tracing divisions between Iranian clerics, including recent assaults on close Montezari associate and presumptive spiritual heir Grand Ayatollah Yousef Sanei, Shafaee speculates:

Yet ironically, the regime may face its greatest threat not from within, but from outside the country. Ever since June's contested election, observers have been keeping a close watch on Grand Ayatollah Ali al-Sistani (who hails from Iran but resides in the holy city of Najaf, Iraq), considered the highest living authority in all of Shiite Islam. Sistani comes from the "quietist" tradition of Shiite theology, one that, unlike the Islamic Republic's ruling doctrine of velayat-eh faqih, holds that clerics should abstain from becoming directly involved in politics. So far, he has refrained from condemning the regime's actions. But his clout is so strong in the Shiite world that, were this to change, the Islamic Republic would arguably no longer face just a political crisis within Iran, but also a crisis of religious confidence among all Shiites.

For now, the influential cleric has shown no signs of weighing in on the unrest. As Ashura came and went, Sistani issued a statement only inviting followers to attend memorial services for the "martyrs" who died in recent terrorist attacks in Karbala and Kazemein, Iraq. Yet there is little doubt that Sistani is watching events unfold in his native land. In November, he met with Ali Larijani, the speaker of Iran's Parliament, and more recently, he defended Sanei in the aftermath of Yazdi's attack.