I was expecting a panicked tone like the despairing Washington Post headline Ilyka Damen found, but Amir Taheri is suprisingly nonchalant about this Ayatollah Sistani:

Sistani's call for elections is seen by some officials in Washington and Baghdad as a definitive rejection of the current plan. But this is a dangerous misreading not only of Sistani's intentions, but also of the role that the Shiite clergy should play in a future democratic Iraq. To begin with, Sistani's statement is a fatwa, which means an opinion, and not a decree or an edict, as some U.S. officials, including L. Paul Bremer, the Coalition's chief civilian administrator, seem to believe.

...In Shiism, as in Islam in general, no religious expert (mujtahid) has the authority to issue either a decree or an edict. There are no popes and cardinals in Islam, and the opinion of one religious expert could be challenged or even contradicted by another's.

[E]ven if, at the end of the day, Sistani remains unconvinced, that should not bring the whole process to a halt. It is unlikely that Iraqi Shiites would be foolish enough to repeat their mistake of 1920 and choose to stay out of the nation's political life. Holding elections is not a religious duty, but a matter of political expediency. The Koran calls for consultation (shawr), and not elections in the Western democratic sense, as a key for legitimizing any government.

You ought to read it all. I've come into contact with enough observant journalists who might take issue with Taheri's near-complete faith in Shiite beliefs and Sistani's magnanimity to be a little puzzled. Yes, I knew that good Shiites believe in secular government - but one can be forgiven, I'd hope, for being taken aback by five-figure crowds chanting angrily in support of a religious leader's political statements. Even more curious is the assertion that Bremer, CPA and most of the Western press have got Sistani all wrong. But Taheri's no fool - if he's not worried, I don't know how much I can be any longer, either. I'm very anxious to see how his predictions match the months ahead.