Will Iraq Become a Divided Country?

In Baghdad today, 44 Sunni prisoners in a government-controlled police station were killed — apparently in retaliation for advances by Sunni extremists with the Islamic State of Iraq and Syria. As forces of ISIS get closer to Baghdad, it appears that Iraq's current leadership might not hold the country together. The unlikely alliance of Iran and the US is urging political unity instead of sectarian warfare, but they're being ignored by Prime Minister Nuri al-Maliki. Others insist that Iraq never was a real country, and that division between Sunnis, Shiites and Kurds is inevitable. Will the current chaos lead to a re-drawing of national boundaries imposed by European colonial powers 100 years ago?