The draft constitution agreed upon by the Shiites and the Kurdish will probably be the text presented to a popular referendum in Iraq but, even if ratified, it is unlikely that it will keep Iraq together.
The reason is that the Arab Sunni minority will do everything to sabotage any document that will make its loss of power official. The insurgency is only one of its weapons; other include boycotting elections, terrorizing the population and all government agencies, hitting Shiite holy shrines and Kurdish organizations. There is every reason to believe that the Sunnis will continue doing so. But looking at the text itself it is clear that it has no chance of ever being implemented.
It has 153 articles (20 times longer than the US Constitution) and most of them are merely a politically correct wish list, probably suggested by American advisors. These articles have little connection with Iraqi realities. The document is full of contradictions. The text stipulates in the same article that no law can be passed that contradicts the rules of Islam and that no law can be passed that contradicts the principles of democracy. In addition, the articles turn regional authorities into institutions that can amend the implementation of federal laws. Likewise, it establishes the creation of representatives of the different regions within the Iraqi embassies thus creating sub-embassies within the embassies.
In fact, this constitution brings about the end of Iraq as it has existed since 1920. The disintegration of Iraq is bound to continue.

Source
Jerusalem Post (Israel)

Long litany of contradictions”, by Shlomo Avineri, Jerusalem Post, August 28, 2005.