I am sure Sadr isn't, but an interim government that is truly "representative" would have him there. Of course, he is a wanted criminal, under Iraqi law, such as it is. But the point, is that those selected I strongly suspect are selected in order to give the whole rather Rube Goldberg exercise a chance to succeed against all odds. And that is how it should and must be.
Sadr? He has a tiny fraction of support amongst the Shia. Its the media spin that has made him out to be some kind of messiah over there - don't buy it. He has perhaps a few thousand militiamen (less every day), his uprising hasn't taken root amongst the people in general. He is nothing more then a thug, like a Crip gang leader. There are 50,000 gang members in Los Angeles, should their leaders be represented on the city council there?