It is all about oil and the money that comes from it. Whichever ethnicity controls Kirkuk, also controls the oil fields around it. Perhaps, if the Kurds displayed a little consideration toward the Sunnis, whose populated areas have no oil, then the Arabs might be more open toward Kurdish expansion and autonomy.
The implications I get from the Kurdish statement is that IRAQ is in reality a Confederation of separate political groups. If you remember U. S. history, you'll remember that there was a Confederation of 13 independent states with a central overgovernment to act aas the point of communication between this new country called the United States and the other countries of the world.
It was during the existance of this confederation that we developed the current Constitution and the First Ten Admendments. This was during a time of PEACE.
When the several states (original 13) approved the Constitution mand the first ten admendments we became truely the United States of America. This was almost a full decade after the end of the Revolutionary War.
It took the War of 1812 to convince England that the United States was here to stay.
Now put the Iraqi in the same position. What would they do?