Apparently the UN guy is interviewing tribal chiefs and ethnic groups getting recommendations. So it really isn't hand-picked by foreigners (although I think we can safely assume that Sadr is not on the short list).
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.
By the way, isn't the UN guy a foreigner?